Home

Complete AKT5 manual - The Agroecological Knowledge Toolkit

1. 0 7 12 4 CREATING A NEW KNOWLEDGE BASE OUT OF A TOPIC 7 13 1 S21 DIFFERENT NODES rrr av miae EE Roe En ded bem eer breue ene Reds 9 22 DIFFERENT UNK S uiro catio a aao oo esu ohin anuo ven este sed pose dox cent ete epu us 9o TAB ZOOM uices dotisa eost dada pes Saad euer O ato EPI CR sade ae EP SP wae nEE 0 2 0 d ZOOMING IN ANG OUl seriea aa eR och rh edaxi eed cH Er 9 2 0 D Cehlte ZOOLTIssesesess enero tasu ETONE ERE EET Ren dun OE IEEE oM EMEN ZMBICT e 8 2 4 a Causes1way Causes2way labelling 8 2 4 b Link TaDellligusc eo oed o e as Ea nr perdes Plo tesece RU es eevee 8 2 4 c Showing only causal or only link statements 8 2 4 d Statement labels esseeeeesseeeeeenennnnne 924e Hiding ldbelss etes ee e pau ded elsi A xS Ree Rh oue es 8 2 5 HIDING NODES AND LINKG 0 ccc cence cence tena ee eeaeeeeaes 8 2 6 REFRESHING A DIAGRAM cc cece ence III I em rrr nnns CREATING SUB DIAGRAM SD i ieseatz seti oi era teu inse teu i Man te CM ERR abou O29 SMOW iUas rrr EE PE opo ME iS CNB Cu EE DIAGRAMMATIC REPRESENTATION essem SORTING STATEMENTS IN THE STATEMENT CARD INVERSE STATEMENTS AND NUMBERING eese OBJECT HIERARCHIES PUES ENAREN CGI MR RR cM PRINTING AND SAVING SEARCH RESULTS PRINTINGINEANDSCAPE atero Lire tdtuR testudo bat apre veia ted 7 14 SAVING A KNOWLEDGE BASE AND
2. Figure 8 15 Diagram of the statement An increase in the amount of animal fodder causes2way increase in the number of animals Knowledge Acquisition 104 Chapter Eight The diagram interface 3 Press Navigate and a doubled ended arrow appears 1 Place this over the node of interest in this case animal number and click with the left hand mouse button All the immediate causes and effects of the selected node will then appear Figure 8 16a This diagram can then be built up step by step by selecting Navigate and then pressing it over each node in turn Figures 8 16b 8 16c and 8 16d demonstrate how the diagram was further enlarged first by clicking the Navigate arrow over animal fodder amount then animal manure availability and finally soil fertility Thus by the repeated use of Navigate on different nodes a diagram can be built up to show a particular aspect of the knowledge base forest fodder private fodder farm labour d awallabilmy amount number animal manure availability Figure 8 16a Pressing the Navigate Figure 8 16b Pressing the Navigate arrow on animal fodder arrow on animal number amount private fodder availability animal fodder amount animal number crop residue amount animal manure availability forest fodder availability tam labour availability animal fodder amount
3. off fam job availability zcale farmer migration population pressure on forest population pressure on forest forest degradation forest degradation intensity intensity forest fodder availability animal fodder amount crop production availability zoil priwate fodder animal_fodder al availability amount ata ure Figure 8 17b Using the Effects Button Showing Figure 8 17a plus all the nodes affected by animal number forest fodder Figure 8 17a Using the Causes Button all the nodes that affect animal fodder amount 8 3 3 a Causes Effects diagrams via the Statements or Search results dialog boxes As with Navigate there is also a Causes Effects button at the bottom of the Statements dialog box and the Search Results dialog box generated by the Boolean Search See above 7 10 1 c Ri If when you use the Causes or Effects buttons on the diagram interface a single new node appears with a red arrow flowing from it then it is concealing other nodes beneath Take the new node and drag it a little way to reveal the other nodes beneath 8 4 VIEWING DIAGRAM STATEMENTS 8 4 1 STATEMENTS FOR THE COMPLETE DIAGRAM To view all the statements represented by any diagram the Statements button on the bottom right hand side of the diagram screen is selected In Figure 8 18 the statements represented by diagram in Figure
4. DOSES RR eee ae ee nba iMac o isa iUt a cu teme odi nei eot eee FORMAL TERMS sarea hubaudes mde nita meDo tution ade edis coxa uot bUseoteats 7 7 1 VIEWING FORMAL TERMG ccc cece eee ce eee Im menn 7 7 2 ADDING FORMAL TERMG ccc ccc e cece eee ee ee sme emen nnnnnns 7 7 3 DELETING FORMAL TERMIS 2 3 2 ceeded einen ies SYNONYM S T MEMOS SELECTING SUBSETS OF THE KNOWLEDGE BASE esee 7 10 1 THE BOOLEAN SEARQGLHL eii I xS Reps oi penus ei ELE En eus 7 10 1 a The use of And and Or ccccccce ee ecceeeeeeeeeeeseneeees 1 10 1 D ING USE ofDrackels ao EIE HEURE i eolanie dese 7 10 1 c Studying the Search Results seseseuesees 7 10 2 USING THE BOOLEAN SEARCH ON OBJECT HIERARCHIES TORPIGS o iveeteccatutesa cs ite lia RUE Ne Uca Rai astern oe ace eee TTL SGREATING A FOP Grori eacie qup AU Ren eae 7 11 2 MANAGING TOPICS eue vasi baee dco puede odd eR S eus TARS USING IOPRKOS i pire eos odi etu tuii rre vba 7 11 4 CREATING A NEW KNOWLEDGE BASE OUT OF A TOPIC TOBRICEBIEIRARGEIBS 4 2 do oan cies ded dtedu quse de epe vas eimi Honest ees T 12 4 VIEWING TOPIC HIERARGHIES taa e E ess i122 OREATING IOPIC HIERARGHIES inre ae uror a eal eet Eod Reds 7 12 3 APPENDING TOPICS TO A TOPIC HIERARCHY
5. They are terms which may need to be defined may have synonyms and in the case of objects may be organised in an object hierarchy e g an oak tree is a type of tree and a tree is a type of plant Formal Term specification Creation of unitary statements Knowledge elicitation Formal representation en gt a MM L p wN EE d MM ere x pud ae TE Ed ban oc ERU Scc Figure 1 2 The creation of a knowledge base There are four principle activities in the creation of a knowledge base as shown in the diagram These occur in sequence bold arrows but evaluation during the creation of the knowledge base and consequent return to previous activities fine arrows means that the process is in fact a series of cycles The process of creating a knowledge base is summarised in Figure 1 2 In principle the process is linear but in practice it is iterative in nature It is important to emphasise that the knowledge base should be evaluated at each stage of development Evaluation of the knowledge base involves assessing the relevance utility and ambiguity of individual unitary statements It also includes checks for repetition and contradiction amongst statements The completeness of the knowledge base and the consistency and precision in the use of terms should also be evaluated continuously during the process of building a knowledge base 1 4 KNOWLEDGE BASE STRUCTU
6. ccccc cece cece eee enna eee eenaeeeeaes 44 2 b Labelling of MOUCS sii esee Iq oben dto Peor ao Tor ERER E Por Porch 4 4 3 EINE cee tile komen eteetudtecad dad orient ec Le ate LR LIU ta ea eod iue 4 4 3 a Attaching information to liNkKS cc ccc cece cece eee e eee aes 4 4 3 6 Stating the meaning of liINKS cece cece ee ence ee eee 4 4 3 c Linguistic correspondence of linked pairs of nodes 4 4 3 d Labelling of liK Seats tuom oia yi REDE RERO re Opa rues 4 4 4 SUBSETS OF DIAGRAMS ci itendUviue Da HOUR ao pe ER ipO en RyoIo 4 5 CREATING KNOWLEDGE BASES THROUGH THE COMBINATION OF EXISTING KNOWLEDGE BASES cssssssesssselele nennen nnn nnn nnns CHAPTER FIVE KNOWLEDGE BASE MANAGEMENT sees Sd INTRODUCTION ier t e d pierdo tex Une a in Rok de Mie Recto a ete 5 2 EVALUATING INDIVIDUAL UNITARY STATEMENTS esee 5 2 1 VALIDITY OF REPRESENTATION esesmmI HH 5 2 2 RELEVANCE AND UTILITY i2 eR ee Eo EE Oe Nx iS Er REID 5 2 3 nuulseipm EE 5 2 3 a Complete specification of meaning 5 2 9 b Context of applicatio 2 ck noses itech os va oU x IM E IER EIU SUE 5 2 9 C Precise Hse oP terns serius Eos aaa a el vb ooo eee 5 2 9 0 IMMIASICsaIMDIQUILY cupo stet or aa bee uM IE Er uc R RU IUe 5 3 EVALUATING SETS OF UNITARY STATEMENTS eese 5 3 1 REP ETI MNO Neste nihcedciau sioe d oda tini weal i
7. 14 3 1 a Entering the Information Source No statement can be accepted by AKT without a source attached so here goes 1 In the New box select the Reference radio button and then press New The dialog box Create a new reference source appears Fill in the details of the authors the name of the journal title and the name of the article as given at the beginning of this chapter When you have completed filling in the details of the dialog box press Save The statements sources dialog box reappears with the source highlighted Press OK Burning can be either a process or an action If it is used as a management tool it is an action otherwise it is a process In any knowledge base it can only be used as one or the other it cannot be entered as both action and process If some statements also refer to burning brought about by natural causes then another term must be found either fire as an object or conflagration as a process In the case of an article the name of the journal should go in the Name box Tutorials 158 Chapter Fourteen Tutorial in creating a simple knowledge base 5 The screen now automatically brings up the New Statement dialog box giving both the formal language representation and the natural language representation of the nodes and link created in the diagram interface Press Save 6 The following message will then appear Are you sure you want to save this
8. If you wish to copy a diagram to a different package for example to be incorporated into a word processing document or to be used in a presentation press the Copy to Clipboard button at the top right hand side of the diagram A message will appear Copy of diagram sent to clipboard You must then open the other package and paste the diagram into to document presentation immediately by selecting Edit and then Paste or Ctrl v If you do not paste it immediately the diagram will be overwritten by the next item that you copy 8 6 4 SAVING DIAGRAMS AS A SEPARATE KNOWLEDGE BASE If you wish to save a particular view and subset of a knowledge base as shown in your diagram as a separate knowledge base then select Save Diagram as New KB This will only save the statements and formal terms shown in the diagram but will retain information about all the sources and object hierarchies in the original knowledge base When creating a new knowledge base in this manner it is wise to go through it carefully and weed out any unnecessary object formal terms hierarchies and sources before starting work on it as a new knowledge base 8 7 DELETING DIAGRAMS If you wish to delete a sub diagram that you have created press Delete Diagram in the main Diagram menu If you wish to delete all the diagrams you have created press Delete all Diagrams in the main Diagram menu If you do this when you next select the main Diagram menu and then Show KB Diagrams th
9. View Tree LIRE Figure 7 35 Demonstrating an object hierarchy in which black soil is the selected object loose soil its sub object and Soil type its parent Ld There are two ways of describing the position of an object in a hierarchy structure Diagram A describes the position in its simplest form All objects higher up the hierarchy than the object in question are superobjects all those below are subobjects A SUPEROBJECTS T OBJECT Y SUBOBJECTS But this structure can be defined more precisely in Diagram B B ANCESTORS T PARENT Tq OBJECT Y CHILDREN V DESCENDANTS An object can only have one parent or immediate superobject but as many ancestors as there are rungs on the object hierarchy ladder above its own position on that ladder On the other hand an object can have many children or immediate subobjects and many descendants on each rung below it on the hierarchy ladder Knowledge Acquisition 68 Chapter Seven Software manual for AKT 7 5 3 6 Detaching objects To detach an object from an object hierarchy enter the relevant Object Hierarchy dialog box and highlight the object to be detached in the Objects in Hierarchy list The object will then appear in the Selected Object box and in the Object box within the Hierarchy Structure In Figure 7 36 this is the object goat Then press Detach ms Object Hierarchy treefodd kb KB Name
10. You should always take care to define your formal terms clearly Even simple terms should be defined as two people may understand something quite different under the same term For example the action clearing could mean clearing of undergrowth clearing of weeds or complete clearing of a site Let us assume that in this case clearing means the complete removal of vegetation from the site 1 Goto the main KB menu 2 Select Formal Terms 3 In the Type box select action 4 Highlight clearing and press Details You can now enter the definition into the definition box 5 Press Save Creating an object hierarchy 7 5 1 You should wherever possible structure the objects to identify any hierarchical relationships between them The creation of object hierarchies allows you to develop a compact knowledge base because they allow knowledge to be recorded at its most general level of application yet be used to consider more specific instances Two of the objects in the knowledge base you are creating here vegetation and crops clearly can be hierarchically associated Furthermore it is obvious from the source text that beans cassava corn plantains rice and yams are types of crop 1 Select Object Hierarchies in the main KB menu 2 Select New 3 In the New Hierarchy Name box enter a name for the object hierarchy You can either enter a name of your own choosing in this case we have called th
11. soil leaching rat nutrient Figure 7 65a The diagrammatic representation of all the causal statements immediately connected to Statement No 32 an increase in the amount of rainfall causes an increase in the amount of soil erosion By selecting Statements on the left hand side of the Diagram screen see Chapter 8 you will get a full list of the statements incorporated into the diagram Figure 7 65b 5 of the 73 knowledge base statements are represented in this diagram 3b an increase in rate of soil erosion causes an increase in rate of soil nutrient leaching hr the system season is winter causes the amount of rainfall is low bh a decrease in frequency of rainfall causes a decrease in amount of rainfall Be an increase in rate of soil erosion Causes an increase in amount of sail erosion Figure 7 65b Statements incorporated in the diagram in Figure 7 65a Knowledge Acquisition 81 Chapter Seven Software manual for AKT It is also possible to use the Causes and Effects buttons In the following example we have highlighted the same statement as above statement no 32 an increase in amount of rainfall causes an increase in rate of soil erosion and then pressed Causes The diagram in Figure 7 66a depicts the causes that flow into statement no 32 and Figure 7 66b presents them in list form 3 of the 73 knowledge base statements are represented in this diagram system aA anincrease in amount of rainfall
12. The incompleteness of a set of unitary statements as opposed to an individual statement see 5 2 3 is assessed through the identification of apparent gaps in the knowledge in relation to objectives Gaps may occur in a knowledge base because the knowledge needed to fill those gaps is unknown or because the relevant knowledge has not been elicited Therefore the identification of gaps demands further knowledge elicitation and if the necessary knowledge is found to be available addition to the knowledge base Completeness can only be defined in relation to objectives in the creation of the knowledge base Even then iterative evaluation of completeness tends to be subjective Generating diagrams provides a powerful means of facilitating the identification of gaps in sets of knowledge For example a diagram constructed as a result of one of a series of interviews with farmers in Nepal provided a set of questions for further interviews such as what are the stem strength properties of the different crop species grown and the different varieties of each species what influence does crop head size have on crop yield What are the consequences of an increase in straw height and does an increase in shade always result in an increase in pest incidence This helped to identify topics for further discussion with the informant 5 3 4 CONSISTENCY AND PRECISION IN THE USE OF TERMS Consistent and precise use of terminology is importan
13. all The tailored primitive will therefore look like this statements search Kb Term object all ListFormalStatements Carry out a syntax check as recommended in the box above For b we need the Statement primitive statements save Kb Statements Enter the primitive details via the Browse Tools Highlight the tool name plus parameters and using Ctrl c and Ctrl v place the primitive as the second line in the new tool add a comma and press carriage return An alternative quicker route is Method 2 as described above 10 2 1 Using Knowledge 138 Chapter Ten Creating your own tools The growing tool now looks like this statements search Kb Term object all ListFormalStatements statements_save Kb Statements When you are combining primitives together to create a new tool there are two points to remember e The parameter names in the tool body must be identical to the parameter names in the tool head when referencing the input or output parameters e When a primitive in the new definition is using the output parameter of a primitive used earlier on in the tool body as an input parameter the two parameter names must be identical Thus the input parameter Statements in this second primitive is replaced by ListFormalStatements the output parameter from the primitive above When amended the second line of the new tool looks like this statements_save Kb ListFormalStatements Do a syntax ch
14. and animal number Figure 8 14 Knowledge Acquisition 103 Chapter Eight The diagram interface we WINAKT current knowledge base soil File KB Diagram Tools Help 100 Title Diagram of the complete soil knowledge base Memo lanting off_farm_job prwate fodder firewood cultivation over crop availability availability scarcity loose_soil i i ze Add node Zoom In Object Zoom Out Attribute Centre Zoom Process Label Mode CE Refresh HERE Undo I dd Link Show Paths O p 2 T TULHULULU Print Window Node Link Navigate Statements Hide a par residue A m Causes Effects Node Link i Causes Effects E H V animal manure availability mulching Show Hide Label t Figure 8 14 Adjacent nodes animal fodder amount and animal number highlighted in the main soil kb diagram 2 Press the Show Paths button to open a new diagram with just the one statement of interest displayed Figure 8 15 we WINAKT current knowledge base soil File KB Diagram Tools Help 102 Title Diagram 102 Memo animal_fodder amount m Add node Object Attribute Process ELE 3 r dd i Print Window Node Link Navigate Statements Hide m Causes Effects Causes Effects Select Diagram Fa i Node Link Show Hide Label t
15. animal number animal_manure availability zoil fertility Figure 8 16c Pressing the Navigate arrow on animal manure availability crop residue amount Knowledge Acquisition 105 Chapter Eight The diagram interface fertilizer forest fodder i amount oe prwate fodder f lab Sail m usage availability availability railh nen compo iea availability appiicata zoil animal_ fodder fertility amount crop animal production number animal manure availability Figure 8 16d Pressing the Navigate arrow on soil fertility crop residue amount 8 3 2 a Navigating via the Statements or Search results dialog boxes It is also possible to build up a diagram using the Navigate facility via the Statements and Search Results dialog boxes Enter Statements via the main KB menu and then highlight the statement around which you wish to build up the diagram and press the Navigate button at the bottom of the screen This will generate a diagram giving the immediate causes and effects of that statement which you can then build upon as described above The principle is exactly the same for using the Navigate option in the Search Results dialog box of the Boolean Search see Chapter 7 section 7 10 1 for an example 8 3 2 b Making a mistake when navigating When you are building up a sub diagram it may be that you inadvertently click the wrong node and get links you did not want in the sub di
16. by highlighting crops so that it appears in the Object box of the Hierarchy Structure section and then pressing Append To 6 Continue as above The principal advantage of the hierarchy you have just created is that it can now be recognised during reasoning that because Soil erosion is not a problem if the soil is always covered with some type of vegetation and Rice is a type of vegetation information from the hierarchy then soil erosion on a site covered in rice should not be a problem 4 Conducting an Boolean Search 7 10 1 A knowledge base may often contain many hundreds of statements see for example the knowledge base treefodd Consequently exploring the contents of a large knowledge base through Statements in the main KB menu or even via the Diagram interface becomes very demanding and confusing However AKT contains a Boolean Search facility that allows you to retrieve sets of statements that correspond to particular criteria Practise searching on an object using the Boolean Search 1 Select Boolean Search from the main KB menu 2 From the Display Kb terms of type drop down menu select object 3 From the list of objects displayed highlight crops and press Select 4 The term crops will appear in the Boolean Search String at the bottom of the dialog box Press Search 5 A Search Results dialog box then appears giving all the statements retrieved containing th
17. parvang hairy caterpilla tree fodder Figure 8 8 Labelling of simple links i e non causal links between nodes in treefodd 2 feed an 8 2 4 c Showing only causal statements or only link statements At the top of the diagram screen are three radio buttons all causal link If you select all all the statements that can be represented in the diagram are represented If you select causal only the causal statements will appear in the diagram If you select link only the link statements will appear in the diagram Try it out by selecting one radio button at a time using the Zoom Out function to see the difference between each selection 8 2 4 d Statement labels Pressing the Label Mode button a second time will reveal the full natural language statement represented by the link and node diagram as in Figure 8 9 If a condition has been attached to a statement via the New Statement dialog box then this condition will appear in the natural language labels Knowledge Acquisition 99 Chapter Eight The diagram interface farmer fertilizer road site land holding govemment_subsid access steepness a decrease in the land ho an increase in the an increase in the access o an increase in the steepness of 5 tamer causes an increasagovemment_subsidy of fertilizer decrease in the prete causes an increase in the rate in Intensity ot crop cultrvatiacauses a decrease in the prce ot ot soll erosion fertilizer intensit
18. visible when setting up a new knowledge base 8 8 1 CREATING A DIAGRAM The method of entering a unitary statement through the diagram interface is best illustrated by example Consider the statement deforestation results in a decrease in the rate of evapotranspiration Deforestation is a process results in is the link and decrease is a value of the attribute rate which describes the process evapotranspiration This statement can be represented on the diagram by two nodes joined by a link As deforestation is a process the Process button from the add node box is selected Click the cursor on the drawing area and a process dialog box appears Figure 8 213 wy Process_dialog Process Node Information Enter Process Name deforestatiorl I No Objects One Object Two Objects OK Cancel Figure 8 21a The process_dialog box The process dialog box requires the process name and whether or not it is attached to one or two objects In this case there are no objects When the box has been completed OK is In this example deforestation is without any accompanying objects Trampling by sheep is an example of a process attached to an object stabilization of bunds by salt grass is an example of a process attached to two objects Knowledge Acquisition 112 Chapter Eight The diagram interface selected On the diagram area a node appears with a green outline
19. Choose type N Mew synonym saved Figure 7 58 Message confirming that private fodder a new synonym has been saved Figure 7 57 Entering a new synonym into the New Synonym dialog box The screen will then revert back to the Synonyms dialog box where the new synonym is now listed under Synonyms Figure 7 59 we Synonyms soil kb KB Mame soil Synonym balaute maato Q A new synonym will only be saved permanently in a knowledge base if you save the knowledge base itself by selecting Save KB or Save KB As from the main KB menu Delete Close Figure 7 59 The new synonym woodland listed under the list of synonyms If you wish to add a definition to the synonym press Details This will bring you directly to the Formal Term Details dialog box see above 7 7 1 and Figure 7 53 where a definition can be added If a synonym is no longer appropriate or desired it can be deleted simply by highlighting it in the Synonyms list box and pressing Delete Note however that if a synonym is already in use as a formal term in the knowledge base i e appears in one of the formal statements then it is not possible to delete it and to remove it you must follow the same procedure as removing an unwanted formal term still in use see above 7 7 3 7 9 MEMOS When opening an existing knowledge base the first dialog box to appear is the Memo dialog box
20. Knowledge Acquisition 70 Chapter Seven Software manual for AKT ms Object Hierarchy treefodd kb E Move Object treefodd kb KB Name treefodd KB Mame treefadd Hierarchy Name Hierarchy Livestock sedet Beet Objects in Hierarchy Hierarchy Structure Super bjects Livestock Close Move To Object Details Selected object Append to large animal chickens Detach On sheep Immediate Sub byects mE small animal none Wiew Tree f object C object subobjects Figure 7 42 Highlighting an object before Figure 7 43 Moving an object to another part moving it within an object hierarchy of the object hierarchy The Move Object dialog box gives the name of the hierarchy in use Livestock and the object to be moved chickens The Move To section allows you to select the hierarchy to which is to be moved and under Object lists the objects within that hierarchy under which the object can be placed At the bottom of the dialog box is the option to move either just the object or the object plus its sub objects In this case the object chickens has no subobject so the object bullet is highlighted Then press Move The following message appears Figure 7 44 ee Object Hierarchy treefodd_kb es Move successful KB Mame treefadd YN chicensmewedtotid Meere Objects in Hierarchy Hierarchy Structure Super byects Livestock Close Object
21. to the Boolean Search String with AND Question why is this Remember to explore the subobjects of tree as well Tutorials 154 Chapter Fourteen Tutorial in creating a simple knowledge base CHAPTER FOURTEEN TUTORIAL IN CREATING A SIMPLE KNOWLEDGE BASE This tutorial guides you through the creation of a small knowledge base and then invites you to try out different ways of exploring it The knowledge represented is abstracted from Bandy D E Garrity D P and Sanchez P A 1993 The worldwide problem of slash and burn agriculture Agroforestry Today Vol 5 3 2 6 The tutorial is only an introduction to AKT please use chapters 7 12 to guide you when you require further information on AKT facilities 14 1 OPENING AKT Open the AKT application An introductory title page will appear Press OK A new screen will appear with a series of menus in the top left hand section Select KB In the ensuing drop down menu select New KB give your new knowledge base an appropriate name e g slash and burn and save it Now that you have an empty knowledge base prepared to receive information we will address the text on which your knowledge base is to be based 14 2 KNOWLEDGE FROM THE SOURCE For the purposes of this tutorial we will make use of the following text as our source knowledge It may be more usual however for source knowledge to be a tape recorded interview The following are extracts from the source text D
22. Figure 7 23 The Memo dialog box attached to a specific statement It is now possible to enter any information about the statement that has not been adequately expressed by formal language There is ample room to write the memo in some detail the scroll bar on the right enabling you to read all the passage Once the memo is complete press Save A message will appear Memo saved O K If you choose to delete a memo select Delete A message will appear Memo deleted If you just want to read a previously written memo then select Close when finished Knowledge Acquisition 62 Chapter Seven Software manual for AKT 7 4 4 DELETING A STATEMENT In order to delete a statement enter Statements via the main KB menu and highlight the statement you wish to delete The statement will appear in the Selected Statement box Then press Delete A message will appear giving the natural language translation of the statement to confirm whether you really want to delete that statement Figure 7 24 Lb Bat EI Ea es WARNING x E un E oi ue 9 X a decrease in price of fertilizer causes an increase in usage of fertilizer AN Ehenernendt dees Are you sure you want to delete this statement Figure 7 24 Message requesting you to confirm whether Figure 7 25 Message you wish to delete the highlighted statement confirming that the statement has been deleted If Yes is selected another message appears Figure 7 25 confirming that
23. Search One statement will appear It is the only statement in the knowledge base which includes both asase kokoo and asase tuntum In the Search Results dialog box press Close In the Boolean Search dialog box press Clear Now do the same thing again selecting asase kokoo and asase tuntum only this time using OR instead of AND Press Search Now you have 30 statements This is because you have selected all the statements that include either asase kokoo or asase_tuntum In the Search Results dialog box press Close In the Boolean Search keep asase kokoo or asase tuntum in the Boolean Search String but this time press the radio button superobject in the Search Options box so that it is highlighted in the same manner as object Press Search once more You will now have 157 statements because besides statements using asase kokoo or asase tuntum you have also selected the statements related to the superobject of asase kokoo and asase tuntum soil Creating a topic otaying in the Boolean Search menu it is also possible to create topics through the Boolean Search String Let us create a topic containing all the statements about red soils asase kokoo all the statements about black soils asase tuntum and all the statements about cocoa Create a Boolean Search String with these three objects Question should you put AND or OR in the search string Then in the box Name of new topic enter soils a
24. This Memo dialog box can also be accessed by selecting Memos in the main KB menu The Memo dialog box should be used as an introduction to the knowledge base The reason it appears as you open the knowledge base is to give users other than the knowledge base developer an immediate general understanding of the knowledge base thus facilitating access to and manipulation of that knowledge Knowledge Acquisition TT Chapter Seven Software manual for AKT es Welcome to the treefodd knowledge base Title of this knowledge base The Tree Fodder Knowledge B ase What this knowledge base is about This knowledge base investigates the farmers and researchers ecological knowledge af tree fodder resources held by the farmers of the eastern hills of Nepal Further Details us Details of the treefodd knowledge base Purpose Methods The primary objective of the research was to develop knowledge based systems KES methods suitable for integrating farmers knowledge in planning interdisciplinary research Initially sisteen knowledgeable Farmers were interviewed in Salma village about tree crop Interaction and tree fodder resource management Knawledge statements from these and from The areas of knowledge investigated were 1 Tapkan water drip and its effects on crops 2 The rukha malila concept and its impact on adjoining crops 3 Fodder quality and its implications on large ruminant productivity Loca
25. decrease in soil fertility Can be broken down into two statements Planting fodder trees causes an increase in soil nutrient uptake An increase in soil nutrient uptake causes a decrease in soil fertility Statements which do conform to the fundamental definition of a unitary statement may often be improved through use of condition For example Thorny leaves are unpalatable may be stated as Leaves are unpalatable if they are thorny This is important because of its subsequent impact on formal representation Formal representation of the former would demand that thorny leaves be treated as an object This is less flexible than a formal statement in which leaves are the object and their palatability and thorniness are two attributes of that object 5 2 2 RELEVANCE AND UTILITY Evaluation of articulated knowledge against objectives provides an important means of maintaining the quality fitness for purpose of the knowledge base Effective filtering of articulated knowledge irrelevant to the knowledge base during knowledge elicitation and formal representation greatly reduces the need for subsequent rationalisation Unitary statements may be relevant in as far as they are concerned with the domain under consideration but irrelevant in that they are not useful in the context of the knowledge base as a whole So for example the statements Manure production influences crop production and Some species of tree fodder have a benef
26. e g Nepal The Tool Body box in this instance remains blank because the tool formal term is a primitive and cannot be broken down into smaller parts The systems tools and user tools will have details of the body of the tools showing the chain of primitives and control structures and possibly simpler systems tools and user tools from which the current tool is constructed On the right hand side of the Tool Details box are three active buttons Test Close and Browse Tools for primitives and system tools The remaining buttons will only be active for User tools Browse Tools allows the user to browse any tool and will be dealt with in Chapter 10 below The Close button removes the Tool Details dialog box The Test button allows you to run an existing tool or try out a new user tool If you press Test a dialog box appears listing all the input parameters which need to be filled in In this case we are searching for the attributes of the object badahar a Nepalese tree in the knowledge base treefodd The input parameters are entered into the template Figure 9 3 Then press Continue The Tool output dialog box then appears Figure 9 4 Under Result are the two attributes describing the tree badahur height and growth rate gu Please specify input parameter s X ge Tool output formal_term 4 m selected treefodd Term Tons Results of running the tool Continue ERES Call farmal term 4
27. some of which are listed below i Assessing farmers knowledge in participatory crop improvement programmes for maize millet Agricultural Research Station Pakhribas eastern midhills of Nepal and cassava maize Corpoica Caribbean Region Colombia in the government sector Methodology 6 Chapter One Overview li ASsessing farmers Knowledge of soil fertility and green manure in an NGO crop improvement programme in the Nepalese Terai LI BIRD ii Assessing farmers knowledge of gap rejuvenation techniques for jungle rubber agroforests in Indonesia ICRAF iv Assessing local knowledge of rubber intercropping practices in Sri Lanka Rubber Research Institute 1 7 THE UTILITY OF THE APPROACH lt is difficult to quantify the utility of output resulting from the application of the knowledge based systems approach Many of the primary outputs are less tangible than the definitive answers produced by a more traditional decision support system which may include quantitative models or expert systems The KBS approach is not intended to produce definitive and therefore testable recommendations Nevertheless trial applications of the approach to date have demonstrated that it can have a real and significant impact on agroforestry based research and development programmes see Box 1 Box 1 Researchers in Nepal design different types of research when they learn about what farmers already know In the eastern mid hills of Nep
28. statement without a condition In this case the answer is yes so press Yes 7 Dialog boxes will then appear asking if you wish to create new formal terms for the various terms just entered Press Yes on each occasion The screen then reverts to the diagram interface and displays the two nodes connected by a link Try entering the other four statements via the Diagram interface Note that clearing like burning is an action and therefore needs an object In this case as well site would be a valid object After entering the first 5 statements and pressing Label Mode on the right hand side of the screen twice to get the full statements you should end up with a diagram something like Figure 14 1 pests site number clearing buming of site causes a decrease In number ot pests clearing of site causes an Increase in temperature ot soil zoil temperature burning of site causes an Increase in temperature ot sail burning of site causes a decrease In levels of disease an increase in temperature of disease zoll causes an increase in rate of levels onganic_matter decomposition organic rnatter decomposition rate Figure 14 1 Diagram constructed from the statements in Table 12 2 This example illustrates one of the most important features of the diagramming approach the way that it helps you to identify ambiguity in the knowledge being represented While the five statements indiv
29. treefodd risen Nama Sore Objects in Hierarchy r Hierarchy Structure gt SuperObjects small anima Close Object Details r Selected object Append to paan Immediate SubObjects Move Copy View Tree large animal ox ject sheep small animal Figure 7 36 Detaching goat from an object hierarchy The following message appears Figure 3 37 asking whether to detach the selected object Press Yes and another message appears confirming that the object goat has been removed Figure 7 38 ax WIN PROLOG T 22 Detach object goat AN Object goat detached Figure 7 37 Message to confirm detaching Figure 7 38 Message confirming that the object object has been detached The object goat is now removed from the object hierarchy Livestock although it still exists as a formal term in the knowledge base If you wish to detach an object which is the head of a sub hierarchy for instance large animal in Figure 7 39 which has buffalo and cattle as sub objects once you have pressed Detach and confirmed that the object is to be detached as in Figure 7 37 above a new message appears Figure 3 40 Knowledge Acquisition 69 Chapter Seven Software manual for AKT ms Object Hierarchy treefodd kb es YIN PROLOG El KE Name treefodd Hierarchy Name 2 Do you wish to detach all the sub objects of large_animal 7 Selected
30. 3 SOME POPULAR MISTAKES AND DIFFICULTIES eese vii 124 ABOUT AK Mires lusticeeus aan dua tdeo s TERR ve nO U Ar LEY E RENTA dotem be M n la aer CHAPTER THIRTEEN A QUICK SIGHTSEEING TOUR AROUND AKT5 CHAPTER FOURTEEN TUTORIAL IN CREATING A SIMPLE KNOWLEDGE 1 amp 1 OPENING AK Je sword ea ten nein Gaeta be od comin en ere nen soedaahets 14 2 KNOWLEDGE FROM THE SOURCE tics sa avcddcnenndasagdaeenetiereeeeetarienianeaeide 14 3 ENTERING KNOWLEDGE INTO THE KNOWLEDGE BASE 14 3 1 ENTERING KNOWLEDGE THROUGH THE DIAGRAM INTERFACE 14 3 1 a Entering The Information Source susessssue 14 3 2 ENTERING KNOWLEDGE THROUGH THE STATEMENT CARD 14 3 3 PLAYING WITH THE KNOWLEDGE BASE esseeeeeeeeee APPENDIX 1 GLOSSARY OF TERMS enr BIBEIOGRADPHEH Y iiio Re Loreto oiii viue ute posed e aes oU etu End viii Chapter One Overview CHAPTER ONE OVERVIEW This chapter is an introduction to using a knowledge based systems KBS approach to support decision making when planning agroforestry research and extension An environment is provided that helps the user to store and access what is known about interdisciplinary topics such as agroforestry as an appropriate starting point for planning research and extension work The knowledge is obtained by talking to people and consulting literature We refer to these pe
31. 8 2 are all listed and it is possible to access the details of each statement by highlighting the statement and then selecting Details At the very top of the pop up menu is stated how many of the formal statements have been drawn in the diagram In this case of a complete diagram 48 out of 73 statements have been used This means that the remaining 25 statements could not be drawn because they were neither causal nor link statements Knowledge Acquisition 107 Chapter Eight The diagram interface 46 of the 73 knowledge base statements are represented in this diagram gt an increase in intensity of cultivation of crop causes an increase in amount of extraction of soil nutrient an increase in government subsidy of fertilizer causes a decrease in price of fertilizer an increase in access of road causes a decrease in price of fertilizer a decrease in price of fertilizer causes an increase in usage ot fertilizer an increase in usage of fertilizer causes an increase in fertility of sail gt an increase in amount of rainfall causes an increase in amount of leaching of sail nutrient an increase in amount of rainfall causes an increase in rate of erosion of soil an increase in steepness of site causes an increase in rate of erosion of sail gt an increase in amount of extraction of sail nutrient causes a decrease in availability of sail nutrient an increase in amount of leaching of sail nutrient causes a decrease in availabilit
32. At the knowledge compilation stage no structured questionnaires should be used The basic questions How and Why are asked during discussions and more questions are framed as the discussion progresses until the farmer cannot explain any further 8 Preliminary analysis of answers from one interview should be used to set up topics and questions for the following interview with the same informant Methodology 14 Chapter Two Knowledge Elicitation 9 Knowledge gained from one interview may be verified through the process of knowledge elicitation with other informants to resolve conflicting information and to assess whether an item of knowledge was idiosyncratic or consistent for the group 10 Where there is some serious contradiction between farmers statements which cannot be explained by differences between the selected strata it is possible to carry out group interviews and put the contradictions to the group for elucidation 11 The attitude of the interviewer towards the farmer is all important and should be one of respect This cannot be overemphasised The interviewer should a Approach the farmer as a student desirous to learn from a teacher Approached in this manner the informant will be more inclined to teach and explain all he knows b Keep an open mind and suspend judgement during knowledge elicitation as indigenous knowledge may be tacit and the interviewer may not know what there is to know c Minimise
33. CHANGING ITS NAME 7 15 MOVING FROM ONE KNOWLEDGE BASE TO ANOTHER CHAPTER EIGHT THE DIAGRAM INTERFACE INTRODUCTION 8 2 VIEWING A DIAGRAM 8 3 2 a Navigating via the Statements list and via Search Results 8 3 2 6 Making a mistake when navigating suseeueuee vi 8 3 3 CAUSES TZ EFFECTS DIAGRAMS hex tod cava ieee eR e or ees 8 3 3 a Causes Effects diagrams via the statements or Search R s lts dialog DOXCSi1 522tin cs niin acusstimasseed ce Iib sube ELSE E cerdo ral 8 4 VIEWING DIAGRAM STATEMENTG 0 cece cceeeee IRR ttt ttti 8 4 1 STATEMENTS FOR THE COMPLETE DIAGRAM r 8 4 2 STATEMENTS FOR A SUB DIAGRAM cnm RR 8 5 MOVING BETWEEN DIAGRAMS 2 ccc cece RR mettre tt ttt trt 8 6 SAVING DIAGRAMS 00 cece cece cece cece eee e cece ee een tmxttrttrvtt trr3crc 11 t3gi 333i 8 6 1 LABELLING DIAGRAMG 0 cece cece cc eeee ence eee ceneeeeeeeeennneeeeeas 8 6 2 MEMO FIELD FOR EACH DIAGRAM cnm 8 6 3 COPYING DIAGRAMS 8 6 4 SAVING DIAGRAMS AS A SEPARATE KNOWLEDGE BAGE 8 7 DELETING DIAGRAMS vices ordre ei eot died Eee nc batan tenn cedediediueGwsasvecaceswe 8 8 CREATING NEW DIAGRAMG cc cece cece eee cece eee eens eee Mtt tette tt t tls 8 8 1 CREATING A DIAGRAM ccc cece ccc cece cece ee eeee metttttt ttt 8 9 EDITING DELETING A DIAGRAM STATEMENT sm RI
34. Figure 7 55 The All Statements message that 25 feeding painyu tree fodder cattle causes the cattle sickness is lahue mute appears having ICE EE pig cines a decrease in productivity of animal selected Show use in hierarchies in the Formal Term dialog box with cattle as the formal term Diagram Navigate Print Statements Figure 7 54 Search Results for the formal term cattle screen display after selecting Show use in statements in Formal Terms dialog box 7 1 2 ADDING FORMAL TERMS It is also possible to add new formal terms unattached to statements to the glossaries via Formal Terms This is of particular use for objects and object hierarchies see 7 5 3 In order to add new formal terms press New A New Formal Term dialog box appears Figure 7 56 ces New Formal Term KB Name treetodd kb Figure 7 56 New Formal Term dialog box The new Formal Term is typed into the top box The Glossary of all formal terms exists to enable you to check that the term or something similar is not already in the knowledge base You select the formal term type from the drop down menu in the Type box The Definition box enables you to add a precise definition of the term as it is to be understood in the context of the present knowledge base Knowledge Acquisition 15 Chapter Seven Software manual for AKT When finished press Save A message will then appear Do you wi
35. Figure 7 70 Topics dialog box To see the details of a topic or to edit a topic highlight the topic and press Details Edit This will bring up the topic details box see above 7 11 1 and Figure 7 68 which gives the Boolean Search String it uses the search mode for objects and a description of the topic If you wish to amend the details it can be done from this dialog box pressing Save when the amendments are complete If you just wish to view the details press Close when you have finished It is also possible to create a new topic by selecting New If you select New the Boolean Search dialog appears as above see 7 10 1 To see the statements attached to a topic highlight the topic in the Topics box press Select so that the topic appears in the Search Topic s box and then press Search This brings up the Search Results dialog box listing all the statements captured by that topic If you wish to delete a topic you must first highlight the topic in the Topics list and then press Delete A message will then appear to confirm whether you want to delete the topic Figure 7 71 Press Yes to confirm 7 11 3 USING TOPICS It is possible to search for several topics at a time If you wish to see statements of more than one topic highlight the desired topics one at a time press Select and then press or before adding another topic to the Boolean Search String If you wish to find only the statements which appear i
36. IF the soil is always covered with some type of vegetation Soil erosion is severe IF soil is not covered with vegetation Soil erosion is very severe on hills An increase in soil erosion causes an increase in the siltation of waterways An increase in the siltation of waterways reduces fish production Weeds are not a problem IF land is regularly fallowed Canopy closure causes the death of weeds 14 3 ENTERING KNOWLEDGE INTO THE KNOWLEDGE BASE These statements can be entered into the knowledge base in two ways through the Show Kb Diagrams interface in the main Diagram menu or through the Statements dialog box in the main KB menu 14 3 1 ENTERING KNOWLEDGE THROUGH THE DIAGRAM INTERFACE It is possible to enter all the statements in Table 14 1 into the knowledge base using the statement card Alternatively all the causal and link statements can be entered through the diagramming interface We will start with the diagramming interface as this helps to ensure unambiguous connections between the individual statements which is very important if a useful knowledge base is to result and can be helpful to the beginner because statements entered through the diagramming interface are formalised automatically As an example of the use of the diagram interface we will enter the statements abstracted from the first paragraph of the text burning helps to control pests and diseases the higher soil temperatures that follow clearing and burn
37. Knowledge representation v Is ita genuinely unitary statement and not a compound statement If the answer to all five questions is not Yes then the unitary statement should be reconsidered In particular statements are frequently found to be compound so that it is necessary to break them down into individual unitary statements Formal representation is justified by the automated reasoning Chapter 6 that it makes possible However the rigorous consideration of the meaning of each unitary statement that is demanded by the process of formal representation is of significant value in its own right 4 2 3 6 Identification of the elements in the statement The second step in formal representation is to identify the objects and parts of objects processes actions links attributes and values in the statement This step is important because knowledge must be explicitly and unambiguously stated in creating formal statements that provide a robust resource for automated reasoning By contrast natural language tends to contain implicit elements A distinction can be drawn between a an implication resulting from inadequately abstracted statements where domain specific knowledge may be needed to achieve more explicit representation and b an implication that the user of the system might understand but which is unacceptable for formal representation The fact that the statement Khasru causes sickness in cattle means that cattle beco
38. Object m Objects in Hierarchy r Hierarchy Structure SuperObjects Close Object Details Figure 7 40 Message displayed when detaching an object with sub objects attached m Selected object Append to Detach Move Copy View Tree Figure 7 39 Detaching an object with sub objects attached The program asks whether or not you wish to detach all the sub objects together with the selected object If you press Yes then in this case buffalo and cattle will be removed from the object hierarchy as well If you press No then another message appears Figure 7 41 which confirms that the object has been detached and its sub objects raised up a level within the hierarchy AN Object large animal detached all its sub objects raised up a level Figure 7 41 Message appearing if an object is detached but its sub objects are left in place 7 5 3 c Moving objects within a hierarchy It may be necessary to rearrange an object hierarchy moving objects to different levels within the hierarchy In the below example Figure 7 42 chickens ducks and geese have been added to the Livestock hierarchy and are directly below Livestock on the hierarchy tree However it would be more appropriate to put them under bird In order to do this highlight the first object chickens in the Objects in Hierarchy list and press Move Copy The Move Object dialog box appears Figure 7 43
39. UK Frost W 2000 Farmers knowledge of soil fertility and weed management in Atwima district Ghana The implications for participatory technology development Unpublished MSc Thesis University of Wales Bangor 91 pp Gupta A K amp IDS workshop 1989 Maps drawn by farmers and extensionists Farmer First Farmer Innovation and Agricultural Research eds Chambers R Pacey A amp Thrupp L A Intermediate Technology Publications London Haggith M Robertson D Walker D H Sinclair F L amp Muetzelfeldt R I 1992 TEAK Tools for eliciting agroforestry knowledge Proceedings of the British Computer Society Symposium on IT enabled Change in Developing Countries London July 1992 Hall R L amp Calder I R 1993 Drop size modification by forest canopies measurements using a disdrometer Journal of Geophysical Research 98 18 465 Hart A 1986 Knowledge acquisition for expert systems Kogan Page London 169 Johnson N E 1989 Mediating representations in knowledge elicitation Knowledge elicitation Principles techniques and applications ed Diaper D Ellis Horwood Ltd Chichester UK Joshi L 1998 Incorporating farmers knowledge in the planning of interdisciplinary research and extension PhD thesis University of Wales Bangor UK Joshi L amp Devkota N 1996 Effect of Ficus auriculata on maize and millet crops at mid altitude bari PAC Working Paper 153 Pakhribas Agricultur
40. Use one or more arithmetic functions to calculate a Result Figure 12 3 Tool Information accessed via the Help menu Once you are familiar with writing tools it is of use as a short cut for copying primitives control structures and systems tools and pasting them into your own tools To do this highlight the tool name but not the tool category or description as demonstrated in Figure 11 3 with attribute_values Kb Attribute Values and press Ctrl c You then return to the tool body of the New Tool dialog box and press Ctrl v to paste it in as described above in Method 2 Chapter 10 2 1 12 2 1 SAVING TOOL INFORMATION AND PRINTING To save the whole Tool Information list to a text file press Print The following message appears Figure 12 4 If you select Yes you will be prompted for the name of a text file and the directory and folder in which to place it If you select No the Print menu will appear in which you can select the orientation number of copies etc as WIN PROLOG 9 W ould you like to S amp VE the output to a text file Figure 12 4 Message asking you whether you want to save the Tool Information to a file Help 148 Chapter Twelve The help facility 12 3 SOME POPULAR MISTAKES AND DIFFICULTIES My knowledge base won t oper properly This is usually a problem with large knowledge bases Check that you have increased the memory available to AKT by adding the correct
41. a practice Technical knowledge is captured by the grammar only in relation to the impact of management actions on the ecological relationships and their Methodology 7 Chapter One Overview impact on management objectives The justification for this emphasis on deeper explanatory knowledge lies in the postulates that e actual management techniques are subject to diverse influences available knowledge about the ecology of the system economic considerations personal preferences and so on and e of these explanatory ecological knowledge may often be portable between sites and across cultures while many other influences are site and culture specific Walker et al 1991 Box 2 Farmers recognition of deficiencies in their knowledge about below ground tree crop interactions While farmers recognised six tree attributes leaf size leaf texture inclination angle crown diameter crown density and tree height that affected tapkan see Box 1 and shade and described causal mechanisms for how each attribute affected them their knowledge of below ground competition was restricted to a rough classification of 40 out of the 90 tree species found on farms as being either malilo enhancing soil fertility and less competitive with crops or rukho competitive with crops Thapa 1994 Causative knowledge about why trees were classified in these ways included only two elements a gross classification of root systems as predomina
42. an 20 4 2001 at 12 51 24 treefodd Figure 9 3 Dialog box with ease ae input parameters filled in for the tool formal_terms Kb pe SeA Term Type Result Result heightregrowth rate End farmal term 4 on 20 4 2001 at 12 51 25 Figure 9 4 Too Output box for the primitive formal terms Kb Term Type Result used on the knowledge base treefodd In the Tool output dialog box it gives the tool name as formal term 4 This is merely a shortened form the 4 referring to the number of parameters input and output associated with the tool This time try out the tool for real Press Close on the Tool output dialog box and Close on Tool Details dialog box The screen will revert to the Tools dialog box The tool should still be highlighted in the list of tools Press Run A dialog box appears requiring you to fill in the input parameters Fill it out as in Figure 9 3 but this time instead of entering attributes in the Type box enter hierarchies Press Continue The Tool output dialog box appears giving a list of all the hierarchies to which the tree badahar belongs All trees Fodder animal type Fodder overripening month Using Knowledge 123 Chapter Nine Reasoning with AKT tools Fodder quality Fodder ripening month Leaf flushing month Leaf shedding month Posilo kam posilo fodder trees crop land trees Ri Although the user has the option to run any tool includ
43. animal fadder causes a decrease in amount of crop residue an increase in scarcity of firewood causes a decrease in amount of crop residue an increase in amount of crop residue causes an increase in amount af mulching of stubble a decrease in depth of soil causes an increase in rate of erosion of soil an increase in amount of erosion of soil causes a decrease in production of crap the system season is winter causes the amount of rainfall is low a decrease in amount of rainfall causes an increase in maisture stress of sail adecrease in availability af nutrient causes a decrease in production of crop an increase in maisture stress of soil causes a decrease in availability of nutrient a decrease in availability af sail nutrient causes a decrease in fertili af soil an increase in distance from home affield causes a decrease in amount of application of compost ir Y EEREEE Figure 8 18 7he diagram statements This statement card offers the following options Most connected node f you press this button a diagram will appear showing the most connected node with all its connections In soil kb the most connected node is soil erosion rate Details If you highlight a statement and press Details it will bring you to the Statement Details dialog box from where it is possible to access the statement formal terms the statements sources and statement memo Delete t is also possible to delete a statement by high
44. as well as keeping a copy in memory If you wish to preserve the newly created tool you must save the tool file as well therefore select Yes If you wish to save the new tool but not in the current tool file then save the tool file under a new name It is possible to save a tool file at any time by opening the main Tools menu and selecting Save Tool File To save it under a different name or in a different folder or different directory select Save Tool File As 10 2 5 CLOSING TOOL FILES In order to close a tool file select Close Tool File from the main Tools menu If you have more than one tool file open the dialog box that appears Figure 10 4 allows you to select the tool file to be closed from the Files list Once selected press OK we Close Tool file Current newtool Selected amp WARNING validationtests x If you wish to Cancel save a tool file you must save it before closing it Files Figure 10 4 Closing a tool file Using Knowledge 130 Chapter Ten Creating your own tools 10 3 AN EXAMPLE OF A USER DEFINED TOOL Below we give an example of a user defined tool from a user defined tool file Ghana Tools which we will run on the treefodd knowledge base Make sure you have the Ghana Tools tool file loaded and then select the tool search_Topic_Statements This tool allows the user to search for a term or several terms in a given topic First we will run the
45. base the statement number will not be the next number available in the list of visible statements but the next number available after the invisible inverse statements This is the reason for any gap in the sequence of numbers between the last visible statement on the statement card and the number given to the first new statement Figure 7 26a below demonstrates this the last number in the original knowledge base was 756 the number allocated to a new statement is 918 That means 162 inverse statements have been created after loading the original knowledge base 753 posila fodder tree tree fodder mainly fed to large animal fod kam posila fodder tree tree fodder not fed ta ox 755 panyu tree fodder not fed Fo cattle PSE cattle fodder tree tree fodder fed to large animal 318 the nutrient value of silage is high Figure 7 26a Demonstrating the gap between the last number of the visible statements and the first number of any new statements The difference 162 is taken up by a set of invisible inverse statements 7 5 OBJECT HIERARCHIES AKT allows you to generate a hierarchy of objects This provides an indexing system for the otherwise unsorted unitary statements that constitute the knowledge base A single knowledge base may contain a number of discrete hierarchies and a single object may occur in more than one hierarchy The creation and manipulation of object hierarchies are controlled by the Object Hierarchies menu under the
46. base to be integrated into current knowledge base Although this tool makes the merging of two knowledge bases extremely easy it should be used with caution Only if the definitions of formal terms used in both knowledge bases are identical is it possible to merge the two knowledge bases without fear of misunderstandings or internal contradictions arising Using Knowledge 127 Chapter Ten Creating your own tools CHAPTER TEN CREATING YOUR OWN TOOLS 10 1 INTRODUCTION The facility for creating new tools in the AKT software is provided for the user whose particular needs are not met by existing tools This chapter introduces the basic principles of creating a new tool and gives some examples 10 2 TOOL FILES 10 2 1 CREATING A NEW TOOL FILE If you wish to create a new tool you must first create a tool file in which to save the new tool s To do so select Tools from the main menu and then New Tool File The following screen will appear Figure 10 1 requiring that the new tool file be given a name The suffix is always automatically mcr for macro Once the file has been named press Save and the following message will appear Figure 10 2 me Name of new Tool file Save in Stools M je e aj lj mcr a update mcr Figure 10 2 Confirming that a new tool file has been created File name newtool mcy Save as type v Cancel ZA Figure 10 1 Naming a new tool file 10 2
47. bearing the legend deforestation The second half of the statement a decrease in the rate of evapotranspiration is an attribute value Therefore the Attribute button is selected from the add node box the cursor is placed in the appropriate position in the diagram area and the mouse clicked The attribute relation dialog box appears Figure 8 21b In this example the attribute relates to the process evapotranspiration so the Process box is ticked As soon as OK is selected in the attribute_relation_dialog the attribute process dialog box Figure 8 21c will appear In this example the process name is evapotranspiration and the attribute name rate There are no objects in the node gg attribute relation dialog x P DER E Altribute Process Made Information Attribute Made Information OK Enter Process Name What does the attribute relate ta M Mo Objects One Object Two Objects OBJECT PROCESS ACTION cancel wi E Figure 8 21b attribute_relation_dialog box Dk Seen Figure 8 21c attribute process dialog box Once the OK button has been selected the main diagram screen will show the following diagram the process node appearing as a oval outlined in green bearing the legend deforestation and the attribute node appearing as a rectangular box with a black outline and with the legend evapotranspiration rate Figure 8 22 we WinAKT new kb File KB Diagram T
48. by selecting Show use in hierarchies us Statement Formal Terms soil kb x ee Formal Term Details ETIN A KB Mame soil Statement Ma 39 Formal Term crop Type object Save Definition Something that is grown by the m farming household for the purpose of Close Formal T err Type all Statement Formal Terms Details 5Syunaenuym s Show use in statements Show use in hierarchies Figure 7 18 Formal Term Details dialog box Close Figure 7 17 The Statement Formal Terms dialog box Fi After editing a statement it is advisable to save the whole knowledge base through the main KB menu For a more detailed description of Formal Term Details see section 7 7 Knowledge Acquisition 60 Chapter Seven Software manual for AKT 7 4 3 6 Appending or detaching additional sources It may be that there is more than one source for a particular statement In that case only the first source is given when the new statement is entered into the knowledge base If the other sources have already been entered into the knowledge base either attached to other statements or via Sources in the main KB menu then they can be appended to the statement at this stage Ri A new source i e one not yet been entered into the knowledge base cannot be attached to a statement via this route It must first be entered into the knowledge base via Sources under the KB menu see sect
49. causes an increase in rate of soll erosion sedzon D hr the system season Ig winter causes the amount of rainfall iz low Dee BS 4 decrease in frequency of rainfall causes a decrease in amount of rainfall Figure 7 66b List of statements represented in Figure 66a Figure 7 66a Causal flow into Statement No 32 Using the same statement no 32 once more we pressed Effects Figure 7 66c is a diagram of all the effects flowing from the statement no 32 and Figure 7 66d presents them in list form 6 of the 73 knowledge base statements are represented in this diagram 35 an increase in amount of sail nutrient leaching causes a decrease in availability of soil nutrient jb an increase in rate of soil erosion Causes an increase in rate of soil nutrient leaching 3r a decrease in fertility of sol causes a decrease in production of crop Sb an increase in amount of soil erosion causes a decrease in production of crop bl a decrease in availability of soil nutrient causes a decrease in fertility of scil BB an increase in rate of soll nutrient leaching causes an increase in amount of soil nutrient leaching Be an increase in rate of soil erosion Causes an increase in amount af soil erosion sol leaching rat d nutrient Figure 7 66d List of statements represented in Figure 7 66c Sail leaching amount nutrient soil nutrient availability sail fertility crop production F
50. e synonyms provides a useful means of allowing a natural articulation of knowledge while still identifying equivalent meaning Synonyms can also be applied to processes attributes actions values and links 5 4 2 RELATIONSHIPS BETWEEN OBJECTS The development of object hierarchies is one of the most demanding tasks in the creation of the knowledge base see 4 3 Regular evaluation of object hierarchies including testing those hierarchies on source communities has proved to be valuable Methodology 45 Chapter Five Knowledge base management Equally assessment of the set of attributes that are related to a particular object or process and the set of values that are linked to an attribute is important in ensuring consistent terminology In one knowledge base for example two separate objects leaves and manure have an attribute texture However the set of values that this attribute can take differs for the two objects soft and hard for leaves loose and firm for manure As a result one or both of the attributes must be renamed to avoid this apparent repetition By contrast both leaves and manure also have the attribute water content but the values that this attribute can take high or low are the same for both 5 4 3 DEFINITION OF FORMAL TERMS The definition of a formal term may be improved iteratively during the creation of a knowledge base After each refine
51. farmland in the eastern hills of Nepal School of Agricultural and Forest Sciences University of Wales Bangor oinclair F L amp Walker D H 1999 A utilitarian approach to the incorporation of local knowledge in agroforestry research and extension Agroforestry in Sustainable Agricultural Systems eds Buck L E Lassoie J P and Fernandes E C M pp 245 275 Lewis Publisher New York southern A J 1994 Acquisition of indigenous ecological knowledge about forest gardens in Kandy district of Sri Lanka MSc Thesis University of Wales Bangor UK Thapa B 1994 Farmers ecological knowledge about the management and use of farmland tree fodder resources in the mid hills of eastern Nepal PhD thesis University of Wales Bangor UK Thapa B Sinclair F L amp Walker D H 1995 Incorporation of indigenous knowledge and prespectives in agroforestry development Part 2 Case study on the impact o9f explicit representation of farmers knowledge Agroforestry Systems 30 249 Thapa B Walker D H amp Sinclair F L 1997 Indigenous knowledge of the feeding value of tree fodder Animal Feed Science Technology 67 97 114 Thorne P J Sinclair F L amp Walker D H 1997 Using local knowledge of the feeding value of tree fodder to predict outcomes of different supplementation strategies Agroforestry Forum 8 2 45 170 Thornes J 1989 Solutions to soil erosion New Scientist 3 June 45 Walker D H Sincla
52. goats 5 3 1 6 Deducible repetition and the use of hierarchies in compacting the knowledge base The identification of hierarchical relationships between objects provides a means of e capturing the hierarchical nature of knowledge e enabling the inheritance of properties by objects up and down the hierarchy which facilitate the development of a compact knowledge base without loss of information and e facilitating hierarchically structured exploration of the knowledge base 5 3 1 c The use of hierarchies in compacting the knowledge base Hierarchies provide a means of compacting the knowledge base They allow knowledge to be recorded at its most general level of application yet be used to consider more specific instances This is achieved by considering hierarchical relationship between terms f for example wheat barley maize and fava beans are identified as being annual crops within a hierarchy the information that annual crops only live for one year is best recorded as generic information about annual crops rather than for each type of annual crop individually This influences the size and tractability of the knowledge base Compare Tables 5 1 and 5 2 Each captures the same information in Table 5 1 the information is explicitly stated in Table 5 2 itis more implicitly captured This is known as property inheritance and is discussed more fully in Chapter 1 7 Methodology 42 Chapter Five
53. increase waterways reduces fish causes2way att value action production fish rate production decrease 15 The weed population does att value action fallowing land frequency regular not become a problem when causes 1way att value weeds population decrease land is regularly left to fallow 16 Canopy closure causes the process canopy closure causes 1way process weeds death of weeds death Select Statements from the main KB menu Then press New Enter the formalised version into the Formal Language Statement box Where there are conditions in the statement as in statements 5 10 11 12 and 15 the condition is entered in the second half of the box headed IF Press Syntax Check to check whether or not the syntax has been properly entered Then press Translate to get a natural language version When you are satisfied press Save kA Warning If you press Close instead of Save you will lose the statement and it will have to be entered again 14 4 PLAYING WITH THE KNOWLEDGE BASE Now that you have created a mini knowledge base the following section gives you suggestions on ways in which to enhance its usefulness and to explore it In each section are numbers underlined and in brackets These are the chapters and paragraphs to which you should refer for instructions on how to carry out the tasks Tutorials 161 Chapter Fourteen Tutorial in creating a simple knowledge base Defining formal terms 7 4 3 a
54. is affected or how it is changed e g Trees influence crop yield Where there is information on the result of the influence this should be captured as a causal statement 4 2 4 e Representation of conditions Statements may be conditional Conditions in the formal language can take the form of attribute value or negative attribute value statements link statements causal statements and comparison statements All these statements are as previously described and may also occur as the main part of a formal statement Conditions may be linked by and and or For example Crops are prone to lodging if there is a strong wind and crop roots are exposed or there is a strong wind and crop stems are weak or equally Crops are prone to lodging if crop stems are weak or crop roots are exposed and there is a strong wind 4 3 FORMAL TERMS SPECIFICATION otructural manipulation of the knowledge base involves the development of consistent and useful glossaries of terms and ensuring the consistent use of those terms within unitary statements In formal language this is expressed as ink influences trees crop yield Methodology 29 Chapter Four Knowledge representation The development of glossaries of attributes processes actions values and link types is automated in AKT Objects are automatically identified but the user is required to identify type of relationships and part of relationships through the creation of obj
55. is unlikely that they have previously been required to describe their knowledge and decision making procedures Additionally much knowledge learnt through experience may be used without a conscious awareness of explicit details Hart 1986 and even conscious knowledge may not be expressed in a way that it can be recognised as such Breuker and Wielinga 1987 This necessarily has implications not only for the elicitation process but also for the subsequent process of formally representing the knowledge for use by others 2 3 INTERVIEW TECHNIQUE Developing a representative abstraction of local explanation of the behaviour of an agroforestry practice or system is a significant undertaking and may involve interviewing 50 or more informants four or five times each Approaches to interviewing are well developed and documented see for example Cordingley and Betsy 1989 Diaper 1989 Cooke 1994 Ethnographic techniques of knowledge elicitation as used by anthropologists such as participant observation etc have been recognised as useful in the development of expert systems because they capture insider knowledge or knowledge described and explained from the informant s point of view Benfer and Furbee 1990 An investigation designed to access the insiders knowledge without relying on shared assumptions and presumptions is known as an emic approach Werner and Schoepfle 1987 This approach is important if knowledge is to be gathered in
56. knowledge base created in an earlier version of the program in a later version of the program but you can t do it the other way round i e open an knowledge base created in a later version of the program in an earlier version 3 My knowledge base how jammed This sometimes happens if you have too many windows open at once To get out of a jam select Ctrl Break In diagrams I cannot move some of the Actions nodes This is a quirk within Prolog To circumvent it make sure that both the vertical and horizontal scroll bars are on zero Select Zoom Out When the action node you wish to move appears on the screen click on it with the left mouse button and drag it It will now move Help 149 Chapter Twelve The help facility C9 whew I load a knowledge base I get loty of messages before the Welcome Page appears When a knowledge base is opened the program checks for duplicate statements and inferred duplicated statements by checking the causes2way statements Usually the messages are for your information only C9 Whew load aknowledge base I get the menage Cannot generate aw inferred statement from statement 42 for example This means that you have entered causes2way where the statement cannot be a causes2way statement You have to check that both parts of the statement are attribute value statements and both parts contain the values decrease or increase If this is not the case then you much ch
57. may be conceptual for example niche or wet season The name of objects in a formal statement are represented by atoms so cow tree and hill are objects represented as atoms However objects in formal statements are usually members of a class of atoms for example cows trees and hills Atoms are represented in lower case only Where an atom in a formalised statement consists of two or more words these should be joined with an underscore e g windfall_ apples The exception to this rule is when the object name in a formal statement begins with a capital letter e g in a proper or Latin name In this case the name should be enclosed between single inverted commas e g Nepal Processes or events describe changes or fluxes in the real world for example the process of soil erosion describes the loss of soil and the process of germination describes the change in a seed from dormancy to active growth Processes like objects are named and are also represented by atoms In some circumstances a process is not associated with any particular objects in the statement e g rainfall alternatively it may be related to one identified object e g erosion is a process related to the object soil or may provide linkage between two objects e g infestation is a process which links the object pests with the object crop uptake is the process that links the object p ant with the object water
58. objects Input parameter A parameter where the primitive or tool expects the parameter to be specified before starting the tool Instantiate To assign a value to a variable 167 Iterative Repetitive Knowledge The outcome independently of interpreter of the interpretation of data information Knowledge acquisition Process of knowledge elicitation and representation Knowledge base An articulated and defined set of knowledge stored on a computer which can be accessed and processed systematically Knowledge based system The combination of a knowledge base set of Knowledge bases and knowledge based system software Knowledge elicitation Articulating knowledge for the purpose of abstraction and representation in a knowledge base Link In a diagram interface the link links two nodes together In causal statements the link is either causes1way or causes2way In link statements the link is defined by the user Local Knowledge Knowledge based on locally derived understanding formed by experience and observation Node These appear in the diagram interface A node represents either an object a process an action or an attribute of an object process or action There are two nodes in a causal statement linked by the reserved terms causes1way or causes2way In a link statement the two nodes are linked by a user defined link Output parameter A parameter where the primitive or tool determines the value and returns this valu
59. one another Knowledge base creation involves abstracting knowledge from the information collected the formal representation of that Knowledge and the specification of hierarchical relationships between terms in the knowledge base As soon as the first statements have been entered into AKT a knowledge base has been created This knowledge can then be evaluated and thereby provides a basis for further knowledge elicitation and representation as well as modification of current representation The process of knowledge base creation involves a tight cycle of knowledge elicitation knowledge representation and knowledge base evaluation NOTE The importance of evaluating the knowledge base after each new round of inputing unitary statements cannot be overemphasised 3 1 PREPARATION Creating a Knowledge base involves specifying the objectives behind it and defining its boundaries 3 1 1 SPECIFICATION OF OBJECTIVES The creation of a knowledge base involves identifying the knowledge to be included These decisions are most effectively and consistently made if taken in relation to an explicit set of objectives The quality usefulness of a knowledge base depends very much upon the objectives being both specific and clear When specifying the objectives it is necessary to strike a balance between the need for precise objectives to guide the knowledge acquisition process and the need to avoid compromising the knowledge acquisition process by adhering t
60. practices particularly traditional practices in the tropics are characterised by their complexity Information about the ecology of such practices and the agricultural economic and social reasons for adopting them is often qualitative sparse and uncertain Development professionals planning research and extension activities need to use such information as effectively as possible but knowledge sources may be dispersed and their information though complementary may not be immediately compatible The Agroforestry Knowledge Toolkit methodology and software provide an environment in which you can create knowledge bases about your chosen topics by collating knowledge from a variety of sources The formal approach to synthesising evaluating and reasoning with knowledge about interdisciplinary topics will facilitate the use of that knowledge in planning agroforestry research and extension This gives a powerful alternative to existing less formal approaches The AKT software provided with this manual provides e aknowledge base structure for storing statements of fact as formal representations e astatement interface and a diagram interface for entering Knowledge into the knowledge base e aset of dialogs for access to the contents of the knowledge base e aset of tools for reasoning with the contents of the knowledge base e anenvironment for creating new tools appropriate to user specific needs The methodology associated with AKT is fle
61. representation of knowledge in the diagram 4 4 3 LINKS As in the statement interface there are two types of link the reserved term links in this case only the reserved term links causes way and causes2way can be represented diagrammatically and the user defined links 4 4 3 a Attaching information to links It is a normal convention in creating node and link diagrams to attach the information to nodes so that links are rarely explicitly labelled This approach may be intuitive but imposes constraints on the diagram When this approach is used in constructing for example causal diagrams the links simply means causes while exactly what is caused is specified in the nodes So for example the node increase in leaf area might be linked by a causes link to increased crop yield This severely constrains further additions to the diagram The fact that pest attack reduces leaf area might need to be included This would only now be possible by adding a further node to the diagram decreased leaf area It is not desirable to have two nodes referring to leaf area one to increase and one to decrease Changes are not necessarily only expressed in terms of changes in the quantity of an attribute A change may also occur in the presence or absence of an object or process Under this scheme there may be clumsily labelled nodes e g occurrence of ovulation or disappearance of frost These problems are overcome b
62. statements Kb Topic Statements The first term of the primitive is an anonymous variable _ and will match with any knowledge base The output variable FormalStatements contains a list of the statements about the topic Using Knowledge 133 Chapter Ten Creating your own tools or lilii Take three ask Type in the terms you want to search for Can use connectives and or SearchTerm This step enables the user to specify the search term terms This primitive is from the Display category and the generic form is ask Question Answer The parameter Question is used to contain a message To distinguish the message from a variable it is written within inverted commas The output variable SearchTerm contains the term s typed in by the user qu liil Take four statements search SearchTerm object FormalStatements TermStatements This step will search the formal statements about the selected Topic for the user specified search term This primitive is from the Statement category and its generic form is statements search Kb Term Hierarchy SearchOption Statementsln ListFormalStatements The first and third parameters are anonymous variables because we are not restricting the search to a particular knowledge base or object hierarchy The variable SearchTerm contains the output from step 3 and the search option is set to object because we are looking for statements that contain the specified search term s and not statement
63. structure does exist between statements AKT uses automated reasoning techniques to a represent each statement by two nodes with a link between them describing their relationship b sort the statements into related sets of nodes and links c draw the resulting nodes and links in such a way that the user can immediately see what relationships exist between the statements Various facilities are also provided in AKT to allow the user to manipulate these diagrams to improve the representation and intelligibility of the knowledge within the knowledge base Key points of chapter one e Agroforestry is interdisciplinary and involves complex decision making for planning and extension programmes e he knowledge based systems approach KBS offers a practical method of capturing storing and retrieving knowledge from diverse sources e Creation of a knowledge base involves knowledge elicitation and knowledge representation using AKT a tailor made software for the purpose e AKT offers both a text mode and diagram interface for knowledge representation and retrieval from a knowledge base e he task language provides a user friendly environment for developing and implementing tools for processing and outputting knowledge from a knowledge base e Several successful applications of KBS approach have demonstrated the use and utility of this novel method in incorporating local and scientific knowledge effectively in planning research and deve
64. subdiagrams Knowledge Acquisition 95 Chapter Eight The diagram interface me AKT current knowledge base soil File KB Diagram Tools Help Diagram of the complete soil knowledge base all cause C link copy to Clipbaa Memo Object Zoom In Zoom Out Attribute Centre Zoom Label Mode Process Refresh BEER Action Undo I a fen Link Show Paths Print Window Delete Node Link Navigate f Statements Causes Effects m Select Diagram 4 Hide TTTUTTTTE Node Link f F m Show Hide Label E Figure 8 2 Part of the diagram for the complete soil knowledge base Figure 8 2 above shows a diagram screen the diagram in the middle of the screen and buttons either side The buttons on the left hand side are for node and link creation and deletion the buttons on the right hand side are for viewing and manipulating the diagrams In this chapter we will first explore how to view and manipulate a pre existing diagram In the second half of the chapter 8 8 onwards we will concentrate on creating a knowledge base via the diagram interface 8 2 1 DIFFERENT NODES If you look at the diagrams generated by soil and treefodd you will see that there are four different node shapes one each for Object Attribute Process and Action respectively and on screen they are also different colours so that the type of node c
65. taken from the statements entered onto the knowledge base However it may be useful to add objects to the object Knowledge Acquisition 67 Chapter Seven Software manual for AKT hierarchy that do not appear in any of the statements but are implied by a more generic term For instance farmers may refer frequently to livestock without mentioning the species For the comprehensiveness and the power of the knowledge base it is nevertheless useful if the researcher can list the species kept under a Livestock hierarchy To add objects that do not appear in the statements you must first add them to the Knowledge base as new formal terms see 7 7 2 and then add them to the object hierarchy If you wish to create a hierarchic structure within the object hierarchy then first select the root or parent object from the list of objects This object will then appear in the Object box in the Hierarchy Structure and objects can be appended to it as before In Figure 7 35 black soil is the head of the sub hierarchy and loose soil is the new subobject ms Object Hierarchy treefodd kb KB Name treefodd Hee tama Selected Object black soil Objects in Hierarchy p Hierarchy Structure Soil type SuperDbjects black soil Soil type loose soil Close Object Details if r Selected object Append to Object k sol D etach ja Immediate SubO bjects Move Copy loose_soil
66. the toolname plus the arguments and press Ctrl c Returning to the New Tool dialog box we move the cursor to tool body and press Ctrl v Looking at the primitive we need to tailor it to our needs The description of the primitive is This tool enables the user to search the complete knowledge base or a subset of it and identify statements that contain any specified formal term synonym source topic or a combination of these items The tool has the same capability as the interactive Kb Boolean Search menu option It collects together in a list any formal statements from the Statementsin list that contain Term or its superobject or subobject depending on SearchOption The user can restrict the effect of the SearchOption to a particular hierarchy by specifying the Hierarchy parameter However this parameter can be ignored for more general searches set Hierarchy If user is not interested in the effect of object hierarchies then SearchOption should be set to object If StatementsIn all then search will be carried out on all statements in Kb knowledge base This description box allows us to see how we can implement the primitive Thus as we are not interested in hierarchies we will replace the Hierarchy variable with the anonymous variable and the SearchOption is set to object Finally as we want the search to be carried out on all statements in the knowledge base the StatementslIn variable is replaced by
67. to the knowledge base The user can add extra sources for a single statement if it is repeated by different informants While some repetition may be self evident the identification of repetition will best be achieved by reference to the objectives of the use of the knowledge base So two different unitary statements using different terms but capturing very similar information may or may not be defined as repetition depending on the potential impact of the different formulations on the use of the knowledge base oelection facilities to identify all statements concerned with a particular formal term or combination of formal terms reveal much repetition Comparing sets of formal statements also reveals repetition as formal representation often causes convergence of apparently distinct statements Such comparisons are most effective when care has been taken to minimise the use of equivalent terms Common causes of repetition are inconsistent use of terms or spelling mistakes For example the following three statements would all be accepted by the knowledge base but would all be identical were it not for inconsistency and carelessness Trampling by goats causes soil creep Trampling by goat causes soil creep Trampling by gaots causes soil creep It is particularly important to decide early on whether objects should be entered into the knowledge base in the singular or plural in the above example whether statements should refer to goat or
68. value for an attribute time or maybe time of year The attribute time refers to the time at which the event occurs The statement Methodology 25 Chapter Four Knowledge representation Soil erosion reduces soil fertility contains implicit values Fertility is an attribute of an object soil while soil erosion is a process with an implicit attribute rate both attributes have implicit values in this case decrease and increase respectively Therefore the statement expressed explicitly would read an increase in the rate of soil erosion causes an decrease in soil fertility Part relationships between objects are also identified at this stage For example in the statement Siris has a light crown oiris a tree species and crown are objects however they are further related in that the crown is a particular part of the object Siris The identification of part of relationships is similar to the identification of type of relationships between objects in the object hierarchy and can similarly be used in reasoning 4 2 3 c Identification of the statement structural type The third step in the process of formal representation is to identify which type of formal statement best captures the meaning of the unitary statement The identification of structural type i e binary statements or attribute value statements was introduced in 4 1 2 However the process can be more demanding during formal re
69. 0 Chapter Fourteen Tutorial in creating a simple knowledge base reduction in soil nutrient att_value part soil nutrients level decrease levels T Leaching causes a reduction process leaching causes1way att_value part soil in soil nutrient levels nutrients level decrease ui A reduction in soil nutrient att_value part soil nutrients level decrease a Harvesting causes a action harvesting crops causes1way levels causes a reduction in causes2way att value soil fertility decrease soil fertility An increase in weed density att value weeds density increase causes2way causes a decrease in crop att value crops yield decrease yield Soil erosion is minimal IF the att value process soil erosion rate minimal IF Soil is always covered with link Covers vegetation soil some type of vegetation 11 Soil erosion is severe IF soil att value process soil erosion rate high IF link is not covered with vegetation not covers vegetation soil 12 Soil erosion is very severe on att value process soil erosion rate severe IF hills att value process soil erosion location hillside and att value site vegetation cover bare 13 An increase in soil erosion att value process soil erosion rate increase causes an increase in the causes2way att value process waterways siltation siltation of waterways rate increase 14 An increase in the siltation of att value process waterways siltation rate
70. 1 oolean options black sail ANGI OF C superobjects Clear Boolean Search String degradation and soil ar erosion and soil ES m Diagram Selection Type r All Statements Causes Effects Navigate Print Statements Figure 7 62 Carrying out a Boolean Search in soil Figure 7 63 Search results from the Boolean Search in Figure 7 62 If you press Diagram in the Search Results dialog box a diagram of all the statements from that search which can be diagrammatically represented appears Figure 7 64 See Chapter 8 for further details about the diagramming interface Knowledge Acquisition 80 Chapter Seven Software manual for AKT rainfall site amount planting planting zoil field amount steepness stubble strip cower_orop depth steepness mulching zoil erosion rate sol leaching rate nutrient zoil erosion amount crop Figure 7 64 The diagrammatic representation of the Search Results in Figure 7 63 It is also possible to highlight any one of the statements in the Search Results and then click on Navigate This option will give you all the immediate causes and effects associated with that particular statement Figure 7 65 gives a diagrammatic representation of all the nodes immediately associated with statement no 32 in the Search Results see Figure 7 63 above an increase in amount of rainfall causes an increase in rate of soil erosion system season
71. 1 Create the Boolean Search String 2 Inthe box marked Name of new topic type in management actions 3 Now press Save in the Save search selection box 4 Inthe Topic Details box press Save once more Go to Topics via the main KB menu and select management actions When the Search Results appear try out the different buttons on the Diagram Selection Type at the bottom of the dialog box 7 10 1 c S DIAGRAM GENERATION 8 Diagramming was used earlier in the tutorial as a means of creating a knowledge base You can also use diagramming as a means of exploring the content of a knowledge base 1 Open the diagram interface by selecting the Diagram from the main menu 2 Try to build up sub diagrams by using the Show Paths 8 3 1 Navigate 8 3 2 and the Cause and Effect 8 3 3 buttons 3 Move between the different diagrams 8 5 4 Give each diagram a different label 8 6 1 Ri oimple attribute value statements and comparison statements cannot be represented in a diagram Printing diagrams 8 11 You may want to print a diagram to illustrate a point just press Print Window on the right hand side of the diagram screen Or if you want to transfer it to anther package before printing it out press Copy to Clipboard 8 6 3 Tutorials 164 Chapter Fourteen Tutorial in creating a simple knowledge base S Printing Statements 7 13 Often it may be useful to print out some of the con
72. 2 1 1 a Scoping The detailed design of a knowledge elicitation strategy is best undertaken during a period of introduction and establishment with the source community Attempts to design a detailed knowledge elicitation strategy prior to fieldwork are inappropriate The scoping period serves to e familiarise the researcher with the source community when applicable and vice versa e allow adjustment of the basic objectives in knowledge base creation through refinement of problem specification e provide a preliminary assessment of the basic and universal information held by the community on the topic in question e help to identify suitable informants for later stages where applicable and e identify parameters within the community that might account for differences in knowledge these parameters may then be used as variables for stratifying the local informants Rapid rural appraisal techniques such as household surveys resource surveys questionnaires and mapping have tended to be used at this introductory stage However scoping does not necessarily require formal surveys and in some cases a few informal conversations with local people may be sufficient to identify the key determinants of variability i e the different strata to be explored and the key informants for the definition stage 2 1 1 6 Definition of the domain The definition stage is used to develop an overall understanding of the domain in question defining boundar
73. 2 OPENING A PREVIOUSLY CREATED FILE To open a previously created tool file select Tools from the main menu then Open Tool File Then browse through your folders and files to select the correct file Highlight the file required and press Open The tool file will then automatically open MEN MEM It is always advisable to keep your knowledge bases and tool files in folders separate from the AKT application 10 2 3 KEEPING TRACK OF THE TOOL FILES It is possible to have more than one tool file loaded at a time simply by creating or opening more tool files To change the tool file in use select Tools from the main Tools menu then User Tools and then the tool file required Figure 10 3 Using Knowledge 129 Chapter Ten Creating your own tools me WINAKT current knowledge base treefodd File KB Diagram Tools Help New Tool File Open Tool File Save Tool File Only the user Save Tool File As Close Tool File tools In the Srna ere eee selected Tool electtool output made File will be Control structures gt Primitives gt System Tools d available for use PSP POP SRP IOS ST User Tools lj e b update Figure 10 3 Changing the tool file in use 10 2 4 SAVING TOOL FILES It is only necessary to save a tool file if you have created or edited existing user tools When you save the new or edited tool a message appears asking if you wish to save an updated tool file
74. A diagram willl appear with the statements nodes highlighted The immediate effect of this statement is unhighlighted rain runoff rate There are no immediate causes of this statement Select the Navigate button on the right hand side of the diagram screen and click the double arrow that appears over rain runoff rate Carefully drag sideways all new Tutorials 152 Chapter Thirteen A quick sightseeing tour around AKT nodes to reveal any further nodes underneath you do this by pressing the left hand mouse button over the node and dragging the node away Select Navigate once more and click on vegetation debris presence Continue to build up the diagram by selecting Navigate each time and clicking on one of the new nodes Question What according to this diagram does vegetation debris burning affect Go to the main menu and select Diagram Hide Diagrams Boolean Search Go to the main menu Select KB Boolean Search Press on the downward arrow on Display KB terms of type and see the different types available Select object Select asase kokoo First press Details to see the term s synonym Then press Close on the Formal Term Details dialog box Now press Select and asase kokoo will appear in the Boolean Search String at the bottom of the dialog box Then press the AND button Then select asase_tuntum and press Select once more lf you want to check the synonym for asase tuntum press Details Press
75. AGROECOLOGICAL KNOWLEDGE TOOLKIT FOR WINDOWS METHODOLOGICAL GUIDELINES COMPUTER SOFTWARE AND MANUAL FOR AKT5 2001 Dixon H J Doores J W Joshi L and Sinclair F L School of Agricultural and Forest Sciences University of Wales Bangor This manual is based on the original Agroforestry Knowledge Toolkit manual Walker D H Sinclair F L Kendon G Robertson D Muetzelfeldt R I Haggith M and Turner G S 1994 Agroforestry Knowledge Toolkit methodological guidelines computer software and manual for AKT1 and AKT2 supporting the use of knowledge based systems approach in agroforestry research and extension School of Agricultural and Forest Sciences University of Wales Bangor The manual was written by Helga Dixon Jim Doores Laxman Joshi and Fergus Sinclair Cite as Dixon H J Doores J W Joshi L and Sinclair F L 2001 Agroecological Knowledge Toolkit For Windows Methodological Guidelines Computer Software And Manual For AKT5 School of Agricultural and Forest Sciences University of Wales Bangor UK ISBN 1 84220 025 9 Acknowledgements This publication includes outputs from research projects wholly or partly funded by the United Kingdom Department for International Development DFID for the benefit of developing countries The views expressed are not necessarily those of DFID R6322 R7264 Forestry Research Programme R7516 Natural Resources Systems Programme FOREWORD Agroforestry
76. An action is similar to a process but is initiated by man for example it incorporates all deliberate actions carried out by managers of an agroforestry practice and is always related to either one object or two e g ploughing is the action related to the object field and application is the action linking the object pesticide to the object crop Statements are formed by combining these three elements with attributes values user defined links and a set of special reserved terms used in the formal language see below 4 2 2 a An attribute describes an object process or action and is generally measurable Thus height rate colour frequency gradient are all attributes An attribute is represented as an atom A value is always attached to an attribute and describes that attribute These values can be in units for example 5 kg 20 hectares 40 kg per ha per year 3 months 7 months or they can be descriptive values such as fall rapid yellow regular steep A value can be represented as an atom a number or as a range A user defined link is a term selected to link two objects two processes or a process and an object when these cannot be linked using the reserved terms see below 4 2 2 a Thus in the statement cows eat grass eat is the user defined link in the statement fruit bats pollinate Parkia biglobosa pollinate is the user defined link A user defined link is represented as an ato
77. B of the specified type below will display all the terms under that type To conduct a Boolean search highlight the term you wish to incorporate from the List of existing terms in KB of the specified type box and press Select from the Boolean options box The chosen word will appear in the Boolean Search String box at the bottom of the dialog box The search is carried out by pressing Search in the Search options 7 10 1 a The use of and and or Further terms can be added to a Boolean Search String by clicking on and or or and then highlighting the next term and pressing Select again The option and narrows a search by limiting the search to only those statements that contain all the terms selected The option or broadens the search by including all statements that contain one or more of the formal terms selected 7 10 1 b The use of brackets lf you use both and and or in your Boolean Search String you must use brackets to construct the arguments logically as one would in algebra Using the knowledge base soil imagine you wished to conduct a search which gave you all statements about degradation and soil and all the statements about erosion and soil To do this you would use brackets in the Boolean search String in the following way degradation and soil or erosion and soil Figure 7 62 7 10 1 c Studying the search results using Diagram Selection Type Once you have formulated t
78. Check IF att value compast amaunt high Translate 1 k Figure 7 11 The New Statement dialog box All unitary statements have to be entered using the formal language Chapter 4 2 in the Formal Language Statement box any conditions are written in the second box the IF box After formulating a statement press Syntax Check If the syntax is correct a box will appear with Syntax Correct if the syntax is incorrect a box will appear as in Figure 7 12 or Figure 7 13 depending on where the error lies da O ntax Error Syntax Error Figure 7 12 Error in the Formal Language Statement Figure 7 13 Error in IF statement The formal statement must conform to the grammar described in chapter 4 2 If you receive the error messages then either the structure of the statement does not conform to the formal grammar or one of the reserved terms e g att_value is misspelt Once the formal language statement has been correctly entered select Translate from the New Statement dialog box for a natural language translation of the formalized statement The natural language statement generated Figure 7 14 will be stylised and will not always read smoothly or be grammatically correct it should however make sense and express the meaning of the unitary statement unambiguously Knowledge Acquisition of Chapter Seven Software manual for AKT m New Statement soil kb Statement Ma 118 KB Mame soll Source s F
79. DGE ELICITATION STRATEGY The framework is divided into four stages Scoping Definition of the domain Compilation and Generalisation The important feature of this four stage strategy for knowledge acquisition in terms of sampling is the separation of knowledge base development the first three stages where a small purposive sample of people are intensively involved and the generalisation stage where a large randomised sample of people is drawn from the target community to explore how representative the knowledge base is COMPILA TION SCOPING 2 DEFINITION GENERA LISA TION gt Objective To refine knowledge To generate a broad To create a coherent To test how acquisition understanding of and comprehensive representative the objectives domain amp define knowledge base knowledge base is of boundaries amp terms farmers generally Informants A broad range of One or two intensive Iterative cycle A variety of activities across the interactions with a repeated interaction questionnaire based and community small number of with stratified sample survey approaches on a purposively selected of key informants sufficiently large and informants knowledge randomly selected activities representation and evaluation of emerging knowledge base sample of informants from the community Figure 2 1 gives an overview of the four stages in the knowledge elicitation process Methodology 11 Chapter Two Knowledge Elicitation
80. Delete Interview Source Plant Scientists 1994a Ea Mame Plant Scientists Year 1384 Canes Year Suffix 4 ms Delete Source treefodd kb Plant Scientists 19943 Are you sure you want to delete this source ewe Gender interviewee DATE Day Figure 7 50 The second step in deleting a Month I Default Source source Figure 7 49 The first step in deleting a Source Figures 7 49 to 7 51 describe the steps taken to delete the source Plant Scientists 1994a from the knowledge base treefodd Plant Scientists 1994a is the sole source for some of the statements within the knowledge base For this reason the message appears saying that it cannot be deleted Figure 7 51 ms Delete Source rreefodd kb Plant Scientists 19842 This source i currently in use and cannot be deleted Figure 7 51 The message that appears if a source is the sole source for a statement and therefore cannot be deleted Knowledge Acquisition 73 Chapter Seven Software manual for AKT 7 4 FORMAL TERMS 7 7 1 VIEWING FORMAL TERMS Formal Terms under the main KB menu brings up a glossary for all the formal terms in the knowledge base Selecting a formal term type object process action attribute value link and comparison from the Type box will bring up the glossary for that type Figure 7 52 Unlike object hierarchies these glossaries can only be flat s
81. Details Figure 7 44 The message E confirming an object has been chickens Selected object 7 ron successfully moved within an dus TENE object hierarchy Object Detach Immediate SubO bjects Mave Caopy View Tree Figure 7 45 An object bird and its three immediate subobjects chickens ducks and geese after they have been moved within the object hierarchy Exactly the same procedure is carried out for ducks and geese so that all three are now subobjects of bird as in the Object Hierarchy dialog box in Figure 7 45 Knowledge Acquisition 71 Chapter Seven Software manual for AKT 7 5 3 d Copying objects between hierarchies It is possible to copy objects with or without their immediate sub objects between different object hierarchies To do this follow the same procedure as above highlighting the object to be copied in the Objects in Hierarchy list in the Object Hierarchy dialog box and press Move Copy In the example below Figure 7 46 we are copying the sub hierarchy bird to the object hierarchy Plant_pest In the Move Object dialog box the present hierarchy name Livestock is in the top Hierarchy box In the Copy To section the hierarchy Plant pest has been selected from the drop down menu The objects in the Object list are now all objects from the Plant pest hierarchy Highlight the object under which the n
82. Diaper D Ellis Horwood Ltd Chichester UK Benfer R A amp Furbee L 1990 Knowledge acquisition lessons from anthropology Al Applications in Resource Management 4 3 19 26 Brandt C J 1989 The size distribution of throughfall drops under vegetation canopies Catena 16 507 Breuker J A amp Wielinga B J 1987 Use of models in the interpretation of verbal data Knowledge acquisition for expert systems a practical handbook ed Kidd A Plenum Press New York Brokensha D Warren D M amp Werner O eds 1980 African rural develooment Indigenous knowledge systems and development University Press of America Chambers R Pacey A amp Thrupp L A eds 1989 Farmer First Farmer Innovation and Agricultural Research Intermediate Technology Publications London Conway G R 1989 Diagrams for farmers Farmer First Farmer Innovation and Agricultural Research eds Chambers R Pacey A amp Thrupp L A Intermediate Technology Publications London Cooke N J 1994 Varieties of knowledge elicitation techniques nternational Journal of Human Computer Studies 41 810 849 Cordingley E amp Betsy S 1989 Knowledge elicitation techniques for knowledge based systems Knowledge elicitation Principles techniques and applications ed Diaper D Ellis Horwood Ltd Chichester UK Diaper D ed 1989 Knowledge elicitation Principles techniques and applications Ellis Horwood Ltd Chichester
83. E BASE 7 14 Now has come the time to close your knowledge base Before closing it you must decide if you want to save the changes you have made to it or not If you do wish to save the changes then select Save KB or Save KB As from the main KB menu Once you have saved the knowledge base select Close KB from the main KB menu If you decide to change or edit the name of any knowledge base it must only be done from within AKT via the Save KB As option If it is done any other way then AKT will not be able to load the knowledge base correctly lf you do not wish to save the changes you have made then go straight to Close KB Once you have closed the knowledge base go to the main File menu and click on Exit AKT YOUR TUTORIAL IS AT AN END THE CHALLENGE IS NOW TO MAKE A KNOWLEDGE BASE OF YOUR OWN Tutorials 166 APPENDIX 1 GLOSSARY OF TERMS AKT Agroecological Knowledge Toolkit the name of the methodology and software Artificial intelligence A field of computer science in which machines are developed and programmed to act as a human brain Automated reasoning Where a machine computer systematically processes statements using rules of inference Boolean search A search mechanism for retrieving statements containing particular keywords Any combination of keywords may be defined using and and or operators Consultant Those from the local community co operating with the researcher b
84. Hausa language in Nigeria it is known as ka danya in the Bambouk language in Senegal it is known as toulou Thus a knowledge base developed on the shea butter tree in West Africa would need to record all the common synonyms for the tree The synonym could also be for a value such as decrease for decline or a process such as furrowing for ploughing The reason it is important to have the synonyms option is that it permits you to draw on all available statements using the formal term or any of its synonyms and prevents accidental exclusion in a topic knowledge base because different terms have been used for the same object process value etc In order to enter a synonym select the main KB menu and then select Synonyms n the Synonyms dialog box that appears select New A New Synonym dialog box appears A list of all the formal terms in the knowledge base appears in the box marked Choose Formal Term Once you select the formal term type from the drop down menu only formal terms of the specified type appear in the Choose Formal Term list From this list highlight the word you wish to give a synonym and then enter the synonym in the New synonym name box Figure 7 57 Press Save A message will appear confirming that the new synonym has been saved Figure 7 58 Knowledge Acquisition 76 Chapter Seven Software manual for AKT N S ce ae New synonym EE Hew Synonym um x New synonym name woodland
85. However this is the more rigorous approach and it often brings new information to the attention of the Knowledge base developer The appropriate method to use depends on the circumstances If the original informants come from the same community as those on whom the representativeness of the knowledge base is being tested then the first approach is sufficient If however the representativeness of a knowledge base created from the information of one community is being tested in other communities then the second approach is recommended Below are sample questions from the two approaches the first taken from research into tea gardens in northern Thailand Preechapanya 1996 Thapa 1994 the second from research into tree fodder resources in the mid hills of eastern Nepal Method 1 1 Cattle do not eat the young leaves of Imperata cylindrica O Agree O Agree with conditions O Disagree O Don t know Conditions specified Pt 2 An increase in shading intensity causes a decrease in the softness of tea leaves O Agree O Agree with conditions O Disagree O Don t know Conditions specified PT 3 The rate of nutrient transfer to tea roots of Castanopsis armata roots is high if Castanopsis armata roots entwines tea roots O Agree O Agree with conditions O Disagree O Don t know Conditions specified PC SOE Methodology 48 Chapter Six Knowledge base analysis Method 2 Which of the following fodder tree species
86. I 8 10 ALTERNATIVE ROUTE TO EDITING DIAGRAMS cmm 8 11 PRINTING DIAGRAMYOS ci eter btud Vet asenw conis uS Dow rire Debet kde eh o tent Vade s CHAPTER NINE REASONING WITH AKT TOOLS sssI gF ANTRODUGTION seit dudar obeb ise vc dud ees udtali e du teol eas Basan tc dd Nasen S TL WBATISJAX TOOL i uu ie eat uc oe I5 eos aplica o etaed eas helene 912 WHAT IDO THE TOOLS DO ebosci ceu Pb MUI Mv or taU dey 912a Whats AX PTrIImIUVO s sessioni oE Oo m RE RIED npe Ue voc Eme rep OE nes 9 1 2 6 What Is A Control Structure eeeeeeennneeene OA 26 NVNat IS AX TOO asco a Nar A RU e vrud p su Ede 92 WORKING WITA TOOLS aiea a ide CRAT a Bone b renee 9 2 1 PPRIMITIVES inicie tu oie eal oe telco ee cued Mai baw oie eine dva oae ret 9 2 1 2 Opening primilllVes ids eror nu ois e Eee see dv ale ete evi ieee 9 2 1 b Different categories of primitives eeeeeesueuessse 9 21 6 The Detalls DOX2 cuee veia duc el died xo ERU ES I rex de vae ms 0 2 2 GONTROLISTRUGTUREJSi s taie dtetwbdie m c eed eet ai eee ee ih rens 9S Oro TEMS TOOLS seco tay b adesto uva void dove toca ued tort cpi Ue Eoi eat 9 31 SOME EXAMPLES OF SYSTEMS TOOLS cccemmRnR CHAPTER TEN CREATING YOUR OWN TOOLS ccsss RR JOE NEUE 9 B 9 6289 a A E a EEEREN UEM RO QU SIBI 10 2 1 CREATING A NEW TOOL FILE eee RR Re 10 2 2 OPENING A PREV
87. IOUSLY CREATED TOOL FILE 10 2 3 KEEPING TRACK OF TOOL FILES eeeernnnnmmm nA 10 24 SAVING TOOL PILES viscera uie cte ene ta Nr em oe E d a 10 25 CROSING TOOL FILE Sirus sereno ninne orca Rer BEER xou Eater ete t ace eite 10 3 AN EXAMPLE OF A USER DEFINED TOOL snnm Ree 10 4 CREATING YOUR OWN TOOL ssssssnmRRRRRRRRRI Rt ttttttttet tti 10 4 1 INCORPORATING EXISTING TOOLS PRIMITIVES WITHIN A NEW TOOL DEFINITION 53 0 6 pta a vaut n ve fos Cow ues e Eo ea o NAE 10 4 2 TESTING THE SYNTAX OF A NEW TOOL hhmnee 10 4 3 AN EXAMPLE OF CREATING A TOOL L essen 10 4 4 TRACING AND TESTING A NEW TOOL ssrhsmmeI tOA4A4a she Trace Dutto mesnedi uEa uU aUe eor ai eeu x Eva xd rade 10 4 4 The Test button Leeeeenn Ree 10 4 5 COMPLETING THE TOOL enmt 109 EDITING TOOLES ceste tette su cued rd en aet oO e UR ce e needed o ede eros 10 6 DIRECTING TOOL OUTPUT TOA FILE een mmm R HH HII CHAPTER ELEVEN INCORPORATING PICTURES AND DIAGRAMS INTO THE KNOWLEDGE BASE n etes ede tw ce bona tmu ene heed LL A ELE CHAPTER TWELVE THE HELP FACILITY sene 12 4 THE FORMAL GRAMMHMR iiissseeRIRIRIRRR R tt tttttttrttt 334 3 tr sis UE RU EEGIGINM IPTE 12 2 1 SAVING TOOL INFORMATION AND PRINTING 12
88. Knowledge base management CHAPTER FIVE KNOWLEDGE BASE MANAGEMENT 5 1 INTRODUCTION Now that the relationships between stages in the process of knowledge base creation have been outlined this section discusses iterative evaluation of the knowledge base during its development The repeated evaluation of the growing knowledge base to drive further elicitation is distinct from the evaluation of the representativeness of the knowledge base considered to be complete in relation to the objectives for its creation see 6 1 and the correctness and utility of its content While these processes have tasks in common their motivations and outputs are different lterative evaluation of the knowledge base occurs throughout the formulation of unitary statements formal representation and the development of lists of formal terms and hierarchies The process demands consideration of both individual unitary statements and sets of unitary statements as well as the specification of formal terms and the relationships between formal terms So for example the statement Orange caterpillars can cause sickness in livestock is incomplete and probably contains implicit meaning Reference to the knowledge source shows that it can be more completely represented as Feeding orange caterpillars to livestock can cause sickness This still does not really capture the meaning of the source knowledge which is that Feeding leaves to livestock can cause sickness to those
89. Knowledge base management Table 5 1 A complete set of 43 unitary statements Crops are economically useful Legumes are economically useful Root crops are economically useful Cereals are economically useful Chick peas are economically useful Pigeon peas are economically useful Cow peas are economically useful Crops are deliberately cultivated Legumes are deliberately cultivated Cereals are deliberately cultivated Root crops are deliberately cultivated Chick peas are deliberately cultivated Pigeon peas are deliberately cultivated Cowpeas are deliberately cultivated Crops are plants Legumes are plants Cereals are plants Root crops are plants Chick peas are plants Pigeon peas are plants Cowpeas are plants Legumes photosynthesise Chick peas photosynthesise Pigeon peas photosynthesise Cowpeas photosynthesise Legumes have roots Chick peas have roots Pigeon peas have roots Cowpeas have roots Legumes have leaves Chick peas have leaves Pigeon peas have leaves Cowpeas have leaves Legumes transpire Chick peas transpire Pigeon peas transpire Cowpeas transpire Legumes are crops Roots crops are crops Cereals are crops Chick peas are legumes Pigeon peas are legumes Cowpeas are legumes Table 5 2 A compacted statement of knowledge based on a hierarchical structuring of the objects reducing the number of statements to 13 Crops are economically useful Crops are deliberately cultivated Crops are plants Legumes photosynthesise
90. Legumes have roots Legumes have leaves Legumes transpire NOOR WD 8 Legumes are crops 9 Root crops are crops 10 Cereals are crops 11 Chickpeas are legumes 12 Pigeon peas are legumes 13 Cowpeas are legumes A mechanism exists for capturing the hierarchical nature of taxonomic statements therefore all the statements not explicitly stated can be deduced by applying the general rules to lower orders of the hierarchy Suppose for example that in a particular knowledge base e four crop species are classified as annual crops e these four are the only annual crops represented in the knowledge base and e all are recorded as only living one year Ensuring that knowledge is recorded at the highest level can greatly reduce the size of the knowledge base Deducible repetition can also occur where the implications of linked sets of unitary statements are explicitly stated in the knowledge base Where a statement contains the assertions that The statement that C Fertiliser application increases crop yield Methodology 43 Chapter Five Knowledge base management is a deducible repetition Similarly it can be logically deduced from b that A decrease in soil fertility causes a decrease in crop yield if oystematic identification and removal of repetition in a knowledge base may often halve the number of unitary statements in the knowledge base 5 3 2 CONTRADICTION Contradictory unitary statements may be of
91. RAMS Any diagrams that you have created will be automatically saved with the knowledge base whenever you select Save KB or Save KB As However if you do not select Save KB but merely press Close KB all the diagrams you have generated will be lost Knowledge Acquisition 109 Chapter Eight The diagram interface 8 6 1 LABELLING DIAGRAMS All diagrams are numbered However as the number of diagrams generated increases it is more useful to give each diagram a title In order to do so select Show KB Diagrams A list of the numbered diagrams will appear Figure 8 20 Highlight the number of the diagram you wish to label and then enter the title into the Title box Press Save Title To save the title permanently press Save KB Ri It is easier to give a diagram a title when you have the diagram in front of you When you have completed a diagram and wish to give it a title keep the diagram open and select Show KB Diagrams This way you can make sure that the number in the top right hand corner of your diagram corresponds to the number that you have highlighted on the list of diagrams ee Select Diagram Selected diagram Tile causes and effects of fodder quantity amp animal nos Select Save Title Close Figure 8 20 Saving titles for the diagrams If the diagram titles has been saved permanently when you open the knowledge base again and select Show KB Diagrams each title will appear in turn in the
92. RE The following sections summarise the main features in AKT used in developing and using a knowledge base These features are described in more detail in relevant chapters that follow Exploring an example knowledge base will reveal most of these features and is recommended for novice users of AKT before starting to develop their own knowledge bases The core content of a knowledge base created within AKT is a set of unitary statements Unitary statements represent knowledge that is perceived to be true by the source of the knowledge even if not scientifically verified Unitary statements are the smallest useful unit of Methodology 3 Chapter One Overview knowledge in that they contain knowledge that is useful without reference to other statements they cannot be broken down any further into useful units of knowledge Examples of unitary statements are Red soils are fertile Trampling by sheep increases soil erosion Cover crops reduce soil erosion Ficus auriculata has large leaves Water drip causes splash erosion Fodder from Artocarpus lakoocha is more nutritious than fodder from Ficus neriifolia 1 4 1 STATEMENT INTERFACE Formal representation of unitary statements in a AKT knowledge base involves using a formal grammar which is designed to allow representation of ecological knowledge By ecological knowledge we mean information about organisms the environment and the interactions amongst them including human actions th
93. SOUC oderit Cte bobina but Unc un Shi Ru E duE diae N CEDE 42 IFOIRMAETEPRESENTATION cutter nete Nha gas Posi estie epe boc RM eus 4 2 1 INATSODUC PON zucca aie its ra de ue eee oia ior Ede Ax ien 4 2 2 THE ELEMENTS OF FORMAL REPRESENTATION 4 2 2 4 Reserved terms eir aote eden osse auo Deua x ERR aimed usus 4 2 3 FORMAL REPRESENTATION OF SINGLE UNITARY STATEMENTS 4 2 3 8 Re Evaluation of the unitary statement 4 2 3 b Identification of the elements in the statement 4 2 3 c Identification of the statement structural type 4 2 3 d Creation of the formal statement sue 4 2 4 SIATEMENT TYPES citur ie eoe te oU absenden dentes tied 4 2 4 8 Attribute value statements ccc cece cece ee enna eee eaes 4 2 4 5 Causal statements cesses 4 2 4 c Comparison statements ccccc ee cce cece eee ee eeeeeeeeeeeens 4 2 4 d User Defined link statements s 4 2 4 0 Representation Of CONnditions ccc cece ce eee ee ence eens IV AS FORWAL TERNS SPECIFICATION icc sascseceeiausoseieedeteeamiaxtadataekentadiagnaxed 4 4 DIAGRAM BASED REPRESENTATION ccccceeeeeeeeea Hm nmn 4 4 1 INTRO DUC TIO rr EE 4 4 2 NODES siscs beste edadatieebun tte si tetra rae pre Lc accede bel Liu eite 4 4 2 a Classification of NOdES
94. These units will be structured according to the context in which they are articulated In the creation of a knowledge base we are more interested in the individual units used to construct that combination than in the combination itself We also need to understand the ways in which these units can be linked It is more important to disaggregate and record the individual units of knowledge that make up a particular statement than to record the original combination The units can be recorded along with enough associated information to allow them to be re combined with others to explain aspects of the behaviour of a system The first step in the process of knowledge representation therefore is to abstract these basic units from the knowledge articulated by the informant These basic units are referred to here as unitary statements 4 1 2 UNITARY STATEMENTS AS BASIC UNITS OF KNOWLEDGE The term unitary statements is used here to refer to the smallest useful units of Knowledge A unit of knowledge is useful if it can be used in combination with other knowledge in reasoning Unitary statements express assertions A statement is not the same as a sentence because different sentences can be used to express the same statement Unitary statements contain knowledge that is useful without reference to other unitary statements but which cannot be broken down into further unitary statements So The biomass production of a plant is propor
95. Title box as you run down the diagram list highlighting the diagram numbers one after the other 8 6 2 MEMO FIELD FOR EACH DIAGRAM For those diagrams which you wish to save it may be worth recording what the diagram shows how it was constructed e g by Navigate or by Causes and or Effects and what is of interest or importance in the diagram For this reason each diagram has a separate Memo button attached in the top right hand side of the diagram screen This memo field functions exactly as the memo fields attached to the sources and the individual statements When you press Memo a dialog box appears with a blank memo field in which you can type all necessary details about the diagram Once you have filled in the memo field press Save to save the information Delete will delete the memo field and Close will close the memo field Ri Remember You only select Close if you were simply looking at the memo field lf you wrote or edited a memo you must always select Save Knowledge Acquisition 110 Chapter Eight The diagram interface 8 6 3 COPYING DIAGRAMS If you wish to copy a diagram open the diagram and then select Copy diagram from the main diagram menu The copy will immediately appear on the screen If you then select Show KB diagrams from the main Diagram menu you will see that the copy appears as the last diagram in the list and has the title Copy of diagram and the number of the diagram that was copied
96. a way that reflects the structure of the indigenous knowledge system and allows the representation of that knowledge system to remain intuitively correct to the informant The alternative approach is an etic one which seeks to understand local practice using external scientific explanations that may have no internal logic for the indigenous informant Knight 1980 2 3 1 SOME GOLDEN RULES FOR INTERVIEW TECHNIQUES 1 Send a formal letter to farmers requesting interviews The time and location of the interview should be arranged to fit in with the interviewee s schedule 2 The interviews should be conducted in the field rather than in the interviewee s home because farmers often need to point to things that they cannot express 3 Itis important to consider whether the season in which the interviews are to be carried out is appropriate Farmers will typically have more time when the harvest is in than at the beginning of the growing season 4 Oneinterview is seldom enough a key informant will need to be interviewed 3 5 times 5 Aninterview should never go beyond an hour as the interviewee will lose interest 6 All interviews should be tape recorded to ensure that the interviewer and interviewee can concentrate on the discussion during the interview and no important points are missed while writing statements The background and contextual information remain intact with the recording which may be used for future reference 7
97. agram The Undo button on the right side of the diagram window allows you to cancel the last operation carried out in the current diagram gt lt WARNING It is important to remember that you cannot simply delete a node from a sub diagram by pressing Delete because that would remove the node not only from the sub diagram but from the earlier diagram and also from the underlying knowledge base 8 3 3 CAUSES EFFECTS DIAGRAMS The Causes and Effects buttons on the right hand side of the diagram window allows you to create a sub diagram showing all the causes of a particular node and all the effects of a particular node in two strokes Select two adjacent linked nodes in the main diagram highlight them and press Show Paths Figure 8 17 uses the same statement as Figure 8 15 An increase in the amount of animal fodder causes2way increase in the number of animals Press Causes and then place the cursor which takes the form of an upward arrow over the first node animal fodder amount and click This gives all the elements that affect animal fodder amount Figure 8 17a Then press Effects and place the cursor which takes the form of a diagonal arrow over the second node animal number and click This will add to the diagram all the elements that are affected by animal numbers Figure 8 17b Knowledge Acquisition 106 Chapter Eight The diagram interface uff farm job prwate fodder availability availability migration
98. aking down the source knowledge into a set of unitary statements may demand considerable interpretation Relying too literally on the exact statements in the source knowledge will tend to result in many statements in the knowledge base that become very difficult to interpret Consider for example In the subsequent fallow period weeds soon die out as the crown of the secondary forest closes A literal abstraction of information might result in the statements that Weeds soon die out in the fallow period Weeds die out when the crown of the secondary forest closes Both statements are fairly literal abstractions and superficially reasonable and useful However as statements in a knowledge base they are problematic as both contain implicit information The term soon is relative to the rate of weed mortality on land which is not fallowed This is clear enough in the source knowledge but not as an explicit statement of ecological knowledge Furthermore in the second statement there is an implicit causality however the statement only really identifies the coincidence of weed die back and canopy closure Interpretation might suggest that we should state instead that Forest canopy closure causes weeds to die back and Forest canopy closure occurs during the fallow period Clearly this interpretation may require validation through further reference to the source knowledge However the knowledge expressed here is more fundamental an
99. al Centre Dhankuta Nepal Knight G G 1980 Ethnoscience and the African farmer rational and strategy African rural development Indigenous Knowledge Systems and Development eds Brokensha D Warren D M amp Werner O University Press of America Lightfoot C De Guia O Aliman A amp Ocado F 1989 Systems diagrams to help farmers decide in on farm research Farmer First Farmer Innovation and Agricultural Research eds Chambers R Pacey A amp Thrupp L A Intermediate Technology Publications London Lundgren B O 1987 Institutional aspects of agroforestry research and development Agroforestry a decade of development eds Steppler H A amp Nair P K R ICRAF Nairobi Paudel K C Pandit R Amatya L K Gurung D B Bhandari H S Harding A H amp Bhattariai S P 1997 Agroforestry Research for Lumle Agricultural Research Centre 1997 2001 37 Richards P 1980 Community environmental knowledge African rural development Indigenous knowledge systems and development eds Brokensha D Warren D M amp Werner O University Press of America Robertson D H Bundy A Muetzelfeldt R Haggith M amp Uschold M 1991 Eco logic Logic based approaches to ecological modelling MIT Press Cambridge Massachusetts oinclair F L Walker D H Joshi L Ambrose B amp Thapa B 1993 Use of a knowledge based systems approach in the improvement of tree fodder resources on
100. al it was assumed during the 1980s by the forest service that the planting of trees on farmland was constrained by lack of appropriate planting material and so nurseries were set up and seedlings offered to farmers Take up of seedlings by farmers was low and it was later discovered through acquiring local knowledge that farmers were in fact already managing abundant natural regeneration on their crop terrace risers Thapa et al 1995 Basically there were plenty of naturally regenerating seedlings farmers cut back those they did not want to develop into fodder trees Furthermore they chose which species they did allow to grow on the basis of a sophisticated understanding of the seasonal feeding value of the fodder they produced Thapa et al 1997 and the extent to which they affected crop yield and soil erosion Thapa et al 1995 aspects that research and extension staff had not adequately considered in choosing nursery stock Farmers also used terminology not always understood by research and extension staff to describe tree crop interactions Perhaps most notably farmers were concerned about canopy modification of rainfall drop size because they thought that larger drops caused higher rates of soil erosion The process of water droplets falling from leaves was locally known as tapkan Not only had research and extension staff been unaware of this farmer knowledge but also it was actually contradicted in the scientific literature which h
101. alent statement number it is possible to have more than one solution if the knowledge base contains duplicate statements from different sources or more than one knowledge base is loaded As the statements should retain their identifying number the Mode variable is replaced by the option numbered The second variable Kb remains the same The variable Original is replaced by the input parameter from the previous primitive ListFormalStatements The variable Converted we can give whatever name we choose in this instance TranslatedStatements would seem appropriate Thus the third line when amended should look like this Using Knowledge 139 Chapter Ten Creating your own tools statements_convert numbered Kb ListFormalStatements TranslatedStatements Do a syntax check and then go on to d Finally to d The tool output will not automatically be displayed in the tool output menu To display the tool output you must incorporate instructions into the tool itself To do this we add the Display primitive show Item Whatever appears in place of the Item variable will appear on the screen We need to show two things i a message saying what the output is and ii the output itself Therefore we will need the primitive show Item twice The tool would now look like this statements search Kb Term object all ListFormalStatements statements save Kb ListFormalStatements statements conve
102. als 151 Chapter Thirteen A quick sightseeing tour around AKT Question How many statements are there on weed control As you can see 107 statements is an unwieldy number To make better use of the knowledge we should look at it in smaller sections which we will now do Press Close Close and Close again to get rid of all the dialog boxes Object Hierarchies From the main menu select KB Object Hierarchies You now see before you a list of the object hierarchies in the knowledge base Object hierarchies are a way of sorting the knowledge creating an indexing system of related objects Highlight tree The Object Hierarchy dialog box for tree appears In the box on the left hand side all the objects in the hierarchy are listed on the right hand side you see the name of the object hierarchy and the immediately subobjects below Press timber_tree in the Objects in Hierarchy list You will see that it now appears in the Object box with the super object tree above and the subobjects odum okoro opam wawa below Press View Tree This gives you the full hierarchy with all its objects and subobjects Now press Close in both dialog boxes Formal Terms Go to the main menu and select KB Formal Terms Press the downward arrow on Type and see the different types of formal terms Select object The formal terms list now gives a list of all the objects in the knowledge base Scroll down and get
103. amount migration T 2 sl T population farm labour zoil est Tehk availability moisture stress sly 2 ob qee forest nutrient degradation availability intensity ale 2 7b forest fodder availability qm animal fodder Azot animal residue pert c al x a 2 cs animal manure amount availability stubble mulching dh Fz Figure 8 6 Diagram with labelling Where there are several links entering one node from the same direction i e where the link line appears red on the screen the symbols e g T2T or 411 may overlap as in Figure 8 7a In order to see the symbols properly select the symbol with the left hand mouse button and drag the symbol a little way to reveal the symbol underneath as in Figure 8 8b Thus T 2 f would indicate an increase in X causes2way increase in Y whilst 1 would indicate something other than an increase or decrease in X causes1way decrease in Y Knowledge Acquisition 98 Chapter Eight The diagram interface Fa d 2 o zoil 1l nutrierit qd availabilty sail nutrient availability l1 2 4 x s zoil zoil fertility fertility Figure 8 7a Overlapping symbols Figure 8 7 b The symbols properly revealed 8 2 4 b Link labelling If the connection between two nodes is not a causal link but a simple link as in sheep eat clover instead of symbols appearing the names of all the links will be displayed Figure 8 8
104. ams for the atw X Purpose To enable identification of requirements for interventions for Land use and livelihoods at participatory technolagy Gogoikram Atwima district Methods Individual and group interviews PRA These diagrams are simple methads were used such as scored illustrations of elements af land use causal diagramming and participate aa and income generating activities at Cogoikrom Location cume emp Timing of May July 2000 Knowledge Collection General Comments Figure 11 4 Selecting a diagram from the Figure 11 3 The second part of the dialog box Welcome Page with the Pictures Diagrams button Using knowledge 145 Chapter Eleven Incorporating pictures and diagrams into the knowledge base Figure 11 5 gives you the diagram selected There is also a memo field in which to explain the meaning of the diagram or picture and its relevance to the knowledge base me Picture of indigenous people atwima Livelihoods of indigenous people at Gogoikrom Farming is the major source of income Cash is obtained mainly from the sale of cocoa maize plantain cocoyam and cassava Rice received as part of sharecropping arrangements with settlers is also sold Cocoa is the most important crop at gt Farm land Figure 11 5 An example of a diagram stored in the knowledge base with an explanation in the memo field In order to incorporate diagrams and pictures into a knowledge base you must adhere
105. an be identified immediately in a diagram Figures 8 3a to 8 3d oll erosion rees flood water pruning level yellow black green blue Figure 8 3a Figure 8 3b Figure 8 3c Figure 8 3d Object Node Attribute Node Process Node Action Node The size of these nodes can be altered by placing the mouse over the node pressing down the right hand mouse button and dragging the mouse either outwards to enlarge the node or inwards to shrink the node This facility is particularly useful if the node text is too large for the original node as in Figures 8 4a and 8 4b Knowledge Acquisition 96 Chapter Eight The diagram interface field field distance from fome distance from _ home amount compost_in_fied compost in field application amount application Figure 8 4a Nodes with Figure 8 4b Enlarged nodes overlapping text 8 2 2 DIFFERENT LINKS On screen the links between nodes are either black or red Black links are single links between two nodes red links appear where two or more links overlap 8 2 3 THE ZOOM To view more of the diagram it is possible to move the scroll bar at the bottom of the diagram screen from left to right and the scroll bar on the right hand side of the diagram up and down However to get a clearer picture of all the interconnections zoom options have been provided 8 2 3 a Zooming in and out Figure 8 2 above is the visible portion of the diagram of the complete soil knowledge bas
106. an idea of the objects in the knowledge base Highlight nfofoa_kwae and press Details This gives you information about nfofoa_kwae which is the local name for secondary forest Press Show Use in Hierarchies You will see that it appears in the object hierarchy land_types Press OK Press Show Use in Statements The 16 statements that appear are all the statements in the knowledge base that mention nfofoa_kwae Under Diagram Selection Type at the bottom of the dialog box press All Statements Introduction to diagrams The diagram that you see before you will show you all the statements that can be represented diagrammatically i e all causal statements Press the Label Mode bution twice This gives you the statements in full You can make the statements more legible by dragging the nodes across the screen to separate them out Question What are the immediate effects of burning nfofoa_kwae If the script is too small just press the Statements button to get a list of the statements then return to the diagram by pressing Close in the Statements dialog box Go to the main menu top left hand corner and select Diagram Hide Diagrams Maximize the Search Results dialog box again Still exploring nfofoa_kwae highlight statement 156 burning of nfofoa kwae causes the trees log presence is positive and press Navigate at the bottom of the dialog box The Navigate button gives you the immediate causes and effects of each node
107. ange the statement to a causes 1 way statement 12 4 ABOUT AKT Finally the last option in the Help menu is a small dialog Figure 12 5 containing the version number of AKT and the Web address where AKT files and information are available There is also an acknowledgement of the people involved in the development of AKT AKTS wer 1 00 C School of Agricultural and Forest Sciences E mail aktbtebangar ac uk University of Wales Bangor URL waw sats bangorac uk attorum Bangor Gwynedd LL57 ZUW UR The AKTS sofware was developed fram VvinAkT Randell et al 1997 which in turn was developed from the original Macintosh version Walker et al 1995 and Kendon et al 1995 Program Design Fergus Sinclair James Doores Laxman Joshi and Catharine Moss Frogramming James Doores User Manual Helga Dixon etal 2001 Figure 12 5 Details about the authorship of AKT As a team may we take this opportunity to wish you all possible success with AKT and may it act as a useful and user friendly support tool in your research and development work and your quest for local ecological knowledge If you have any difficulties or queries you can contact us directly at akt5 bangor ac uk Help 150 Chapter Thirteen A quick sightseeing tour around AKT CHAPTER THIRTEEN A QUICK SIGHTSEEING TOUR AROUND AKT5 The purpose of this exercise is to let you have a go with a good knowledge base and see what can be done with it For this exercise w
108. armers 19973 Gave Natural Language Close cultivation of sandy_soil causes an increase in production of crop 4 rs S Ounces F the amount of compost is high q F Formal Terns Memo Formal Language Statement actian cultivatian zandy soil causes way att value crep production increase 4 Suntax Check F att value campoast amount high 1 k Figure 7 14 Translation of the formal statement into natural language When you are satisfied with the statement press Save If you save a statement without a condition a dialog box will appear as in Figure 7 14a asking you to confirm that you wish to save a statement without a condition If you select No you will return to the new statement dialog box If your statement includes any formal terms new to the knowledge base before the statement is saved a dialog box will appear asking you whether you want to create the new formal term Figure 7 14b A new dialog box will appear for each new formal term The purpose of this is to make you aware that you are creating a new formal term to cut down on the number of synonymous terms used and the number of spelling mistakes es YIN PROLOG Ei m WIN PROLOG Ex so a 2 Are you sure you want to save this statement without a condition 22 Do you with to create a new formal term silage Figure 7 14a Saving a statement without a condition Figure 7 14b Creating a new formal term within a statement If you press Yes Figure 7 14b then a ne
109. as appropriate Sinclair et al 1993 While this is possible with the current software a clear vision of the range of tasks for which the knowledge base is intended is required from the outset Thus an effective set of criteria can be developed to enable decision making during knowledge representation This clarity of purpose is particularly important where more than one individual is involved in creating the knowledge base or where the knowledge is derived from more than one group of informants For example comparison of the knowledge bases created to date suggests that a list of key processes might be identified which are likely to be important in any description of the ecology on an agroforestry practice While the terminology used in the lists of processes of these different Knowledge bases is not immediately comparable it is apparent that the same fundamental processes shading rainfall interception and nutrient cycling for example are being described in each knowledge base Starting from a common knowledge base template may facilitate the creation of Knowledge bases that are generic in their content and can be combined successfully Earlier approaches to develop templates at a statement level Haggith et al 1992 proved difficult to implement but this more flexible higher level approach may prove effective in facilitating the develooment of coherent and comparable knowledge bases Methodology 8 Chapter One Overview Box 3 Compara
110. at influence them see Chapter 4 2 and Table 4 1 The formal grammar comprises four fundamental types of statement attribute value statements causal statements comparison statements and generic link statements Each statement may be composed of elements from the formal terms described above objects processes actions attributes values and links For example a formal representation of the statement The germination percentage of oak seeds is high if the air temperature is between 15 and 25 C and the moisture content of the seed is between 80 and 90 would look like this att value process part oak seeds germination percentage high IF att value atmosphere temperature range 15degreesC 25degreesC and att value seed moisture content range 80 9095 Each statement is tagged with its source s giving details of the literature or interview from which was derived Most statements are only valid in certain conditions The general format of a unitary statement is therefore assertion IF conditions sources The formal representation of each statement is retained within the Ps appel base Formal terms in the formal statement are identified automatically by a parser which checks the syntax of the formal statements Each new formal term is added to the lists of terms in the categories of object process action attribute value or user defined link While developing the knowledge base you can order relat
111. atically any statements entered through the statement card must be formalised manually The process of formal representation requires some practice Read through Chapter 4 part 4 2 which takes you through formal representation step by step then try to formalise the extracted statements given in Table 14 1 Table 14 3 gives a formal version for each of the statements in Table 14 1 There are no definitive correct answers in formal representation although there are certainly incorrect ones Ri NOTE Remember to use the underscore not a hyphen when writing formalised statements e g att value Table 14 3 Formal versions for each of the extracted statements in Table 14 1 __ Extracted Statements Formalised Statements action burning site causes1way numbers of pests att value pests numbers decrease action burning site causes1way crop disease level att value crops disease level decrease P inson temperare o action clearing site causes1way in soil temperature att_value soil temperature increase An increase in soil att_value soil temperature increase causes2way temperature causes an att_value process organic_matter increase in the rate of decomposition rate increase decomposition of organic matter 5 Nutrient availability is high for att_value site nutrient_availability high IF two years after burning att value site time_since_burning range 0 years 2 years Tutorials 16
112. att value Object Attribute Value AttributeStatement att value ProcessBit Attribute Value AttributeStatement gt att value ActionBit Attribute Value Cause AttributeStatement Cause ProcessBit Cause ActionBit Cause gt Object Cause gt not Cause ActionBit gt action Action Object Object ActionBit action Action Object Effect AttributeStatement Effect ProcessBit Effect ActionBit Effect gt not Effect Process bit process Process Process bit gt process Object Process Process bit gt process Object Process Object Thing Object Thing ProcessBit Attribute atom Process gt atom Link gt atom Object atom Object part Object Object Action atom Comparison Atom where Atom is an element of the set greater than less than same as different from Value Atom Where Atom is an element of the set increase decrease change no change Value Atom Value Number Where Number is either a floating point number or an integer Value range Value Value Methodology 22 Chapter Four Knowledge representation 4 2 2 THE ELEMENTS OF FORMAL REPRESENTATION There are three basic elements to formal representation objects processes and actions Objects processes and actions can be considered to be the fundamental elements around which the formal statement is structured Objects are normally physical items in the real world like trees and crops but
113. be added by selecting Memo and typing the information into the Memo attached to source dialog box Figure 7 9 In the case of an article the name of the journal should go in the Name box Knowledge Acquisition 55 Chapter Seven Software manual for AKT me Memo attached to source 1999a KB name soil kb Delete Close P Figure 7 9 The Memo attached to source dialog box in which extra information about the informant or the reference can be added 7 4 1 6 Sources already entered If entering new statements but from a source already in the data base check that the correct source is highlighted and appears in the Selected source box of the Information Source dialog box as in Figure 7 10 below Then press OK Information Source Please select information source Selected Source Gurung 1997 a Sources Mew Farmers 1 337a Gurung 139373 E Interview t Reference OK Close Details Delete Figure 7 10 Highlighting a source already entered Knowledge Acquisition 56 Chapter Seven Software manual for AKT 7 4 2 ENTERING A NEW STATEMENT Figure 7 11 is an example of a newly entered statement oe New Statement soil kb Statement Ma 118 KB Mame soil Source s Farmers 133 a Gave Natural Language Close Sources Formal Terms Memo Formal Language Statement acton cultvation sandy soil causes way att value crop praduction increase 4 Synta
114. ber C school af Agricultural and Forest Sciences University of Wales Bangor Gwynedd LL57 ely x m Figure 7 1 Title page of AKT Click on OK A large blank screen appears with the main menu in the top left hand corner as in Figure 7 2 Knowledge Acquisition 51 Chapter Seven Software manual for AKT gg AKT no knowledge base loaded File KB Diagram Tools Help Figure 7 2 The main menu Move the cursor arrow to KB and press The following menu appears Figure 7 3 Eg AKT current knowledge base treefodd File KB Diagram Tools Help New KE Open kb cave Kb cavae Kb As save Topic as Kb Close Kb Select Kb Boolean Search Formal Terms Object Hierarchies Memos SOUICES statements Synonyms Topics Topic Hierarchies Figure 7 3 The main KB Knowledge Base menu A knowledge base file must be opened before work can begin either by creating a new file New KB or by opening an existing file Open KB Other file management options allow the current file to be closed Close KB the file to be saved Save KB or the file to be saved under another name or in another location Save KB As There is also the option of saving all the information about one topic as a separate knowledge base Save Topic as KB s WARNING When adding new statements or diagrams to the knowledge base the programme does not automatically sa
115. bject ploughing to field harvesting to crop etc Although the grammar allows an action to stand alone this is less useful in terms of the information it imparts and should therefore be used only sparingly rate percentage seed germinating within a given time Methodology 27 Chapter Four Knowledge representation decrease 1 process soil erosion causes1way att value soil fertility decrease action ploughing slopes causes1way att value process soil erosion rate increase Conifers causes 1way att value process soil acidification rate increase i att value stem thickness decrease causes2way att value stem strength 2 att value process seed germination rate increase att value process rainfall rate increase causestway att value surface moisture value increase Not all causal statements describe a change in the value of an attribute Y may also be a process in other words something an attribute statement an action a process or an object causes a process to take place for example Object causes process Conifers cause soil acidification Y may also be an action for example Attribute statement causes action An increase in pest numbers causes the application of pesticides Nevertheless we are creating ecological knowledge bases and as actions are usually determined by a far more complex set of factors than ecological conditions alone a farmer s decision to apply pesticides for example will b
116. cape In order to do so select Properties and then Basics from the printer details dialog box Figure 7 89 and select the Landscape radio button under Orientation Then press OK This will return you to the Print dialog box as above Figure 7 88 Outside F5 laser Properties 2I x Finishing Effects Paper Basics Configure Quick Sets Copies fio cop Orientation Portrait C Landscape About s Hotateu D HEWLETT PACKARD Cancel Help Figure 7 89 Selecting the Landscape option in print Properties 7 14 SAVING A KNOWLEDGE BASE 7 14a Saving a knowledge base on the hard drive If you wish to save any additions or alterations to a knowledge base you have made since creating it or opening it you must always select Save KB before you close the knowledge base down by selecting Close KB 7 14b Saving a knowledge base to a floppy disk or a cd If you wish to save a knowledge base to a floppy disk or cd do not save it directly to the disk because it will take a very long time Save it to the hard drive first and then using Windows Explorer select the saved file press Ctrl c open the floppy disk drive cd drive and press Ctrl v 7 14c Saving the knowledge base under a different name If you want to change the name of a knowledge base or create two versions of a knowledge base then before closing the knowledge base you should select Save KB As This allows you to rename the know
117. caterpillars and other sicknesses might be significant All these factors will affect the formal Note that in this case on_leaves is seen as a value of the attribute location Methodology 37 Chapter Five Knowledge base management representation of the knowledge and depend on the consideration of this unitary statement with other unitary statements in the knowledge base Considering a unitary statement in the context of the other unitary statements in the knowledge base may reveal repetition contradiction incomplete sets of unitary statements or inconsistent use of the terms In this example there are statements that Green caterpillars cause sickness in livestock Black caterpillars cause sickness in livestock There is also information in the object hierarchies that there are three types of caterpillars orange black and green If it is assumed that this is the finite set of caterpillars in this context then the three can be replaced with the single statement that Feeding leaves to livestock causes sickness if there are caterpillars on the leaves If it is suspected or found that there are other types of caterpillars that may not or do not cause sickness if fed to livestock the three statements may be replaced by the single statement Feeding leaves to livestock causes sickness if there are caterpillar on the leaves and those caterpillars are green or those caterpillars are black or those caterpillars are
118. causes light or heavy tapkan effects on crops Fodder tree species Heavy tapkan Light tapkan Don t know Nebharo Ficus roxburghii Badahara Artocarpus lakoocha Gogun Saurauia nepaulensis Utis A nus nepalensis Amalla Embilica officinalis Rato siris Albizia julibrissin What is it about these fodder trees that causes tapkan effects on crops to be light or heavy Fodder tree species Reasons for Reasons for Reasons for causing heavy causing light not knowing tapkan effect tapkan effect Nebharo Ficus roxburghii Badahara Artocarpus lakoocha Gogun Saurauia nepaulensis Utis A nus nepalensis Amalla Embilica officinalis Rato siris Albizia julibrissin Key points of Chapter 6 Knowledge from a purposively selected sample of informants needs to be checked to see whether this is a true representation of the knowledge of a wider community before this knowledge can be used in research and extension programmes Two approaches are available for testing representativeness of knowledge in a knowledge base 1 A questionnaire listing a selection of the statements with the options Agree Disagree Don t Know 2 Open ended questions given to a selection of new informants to compare their answers with those already given and used in the knowledge base Stratification of the source community for testing the representativeness of the knowledge base can reveal differences in the source community regarding knowle
119. chy dialog box gives the structure of the hierarchy Figure 7 83 Knowledge Acquisition 89 Chapter Seven Software manual for AKT ms Topic Hierarchy treefodd eg Append Topic x Kb Mame treefodd Topic Hierarchy AN Topic not a subset of SuperT opic Topics in hierarchy Topic Hierarchy Structure Supertopics Close farmers_fodder Topic Details Figure 7 84 Message appearing when it is not possible to append a topic to a topic hierarchy Append to farmers crop farmers fodder Figure 7 83 The subtopics Tarmers crop and Tarmers fodder appended to the topic hierarchy Tarmer Topics can only be appended to a topic hierarchy if they are a subset of that topic hierarchy In other words their Boolean Search String can only contain formal terms sources also included in the topic hierarchy In this case farmers crop and farmers fodder are both subsets of farmers If you attempt to append a topic with a Boolean Search String which is not a subset of that of the super topic for instance if we try to append scientists as a sub topic of farmers a message will appear warning you that the topic is not a subset of the super topic Figure 7 84 7 12 4 CREATING A NEW KNOWLEDGE BASE OUT OF A TOPIC HIERARCHY Just as one can save a topic as a new knowledge base it is also possible to save a topic hierarchy as a new knowledge base In order to do so highlight the topic hierarchy in quest
120. conditional Number of causal statements 8a of which 4 are conditional Number af comparison statements 1 af which are conditional Number of link statements of which are conditional End kb report 2 anzl at 1253 hrs No of Tools 1 Figure 9 7 The dialog box for Knowledge Evaluation System Tools Figure 9 8 Output screen for kb report 1 on the soil knowledge base This is a simple system tool requiring you only to press Run and enter the name of the knowledge base to be interrogated Alternatively it can be incorporated within a user tool as just part of a more extensive user report Running the tool gives a report Figure 9 8 on how many statements within the specified knowledge base fall into the following categories All statements of which n number are conditional Simple attribute value statements of which n number are conditional Causal statements of which n number are conditional Comparison statements of which n number are conditional User defined Link statements of which n number are conditional b System tool category Query statement query Kb This tool allows the user to analyse the knowledge base by submitting a query of arbitrary complexity The query is specified in the form of a formal statement that conforms to the AKT grammar for example typing att value Ob1 Att1 Val1 causes2way att value Ob2 Att2 Val2 in the query box will allow the user to find all the causal state
121. creen Move your cursor onto the drawing area and click to create an action node A dialog box will appear asking for details of the action Enter the action name burning and then look at the object boxes There are two options One Object or Two Objects In this case it is an action without a specified object but as all actions are accompanied by objects it is necessary to refer to the object being burnt In this case site or field could be used Tick the One Object box and enter site Press OK On the diagram screen a node appears bearing the legend site burning Select the Attribute button from the Add node box to create the second node An attribute relation dialog box appears The attribute can relate to three things objects processes or actions In this case it is related to an object pests Tick the Object box Press OK An attribute object dialog box then appears opecify number as the attribute and pests as the object Press OK Now select the Link button from the Add link box Move the cursor to the site burning node left click and hold the mouse button down drag the cursor to the pests number node and release the mouse button A Choose Link dialog box now appears In this case for Link type choose causesiway and for Effect Value in the Parameters box choose decrease Press OK The Information Source dialog box now appears
122. crete topic hierarchies and a single topic may appear in more than one hierarchy When you first open your knowledge base the Topic Hierarchies dialog box can be accessed directly via the Welcome Memo by pressing the Topics button This is to give the user an idea of what topics are covered by the knowledge base If you wish to return to it later you enter Topic Hierarchies via the main KB menu 7 12 1 VIEWING TOPIC HIERARCHIES In order to view a topic hierarchy enter Topic Hierarchies via the main KB menu The Topic Hierarchies dialog box appears listing the topic hierarchies that exist If you highlight one of the topic hierarchies the Topics in selected hierarchy box produces a list of topics within the topic hierarchy Figure 7 76 me Topic Hierarchy soil ess Topic Hierarchies zoil Kb Mame soil Ca ii A Topics in hierarchy Topic Hierarchy Structure SoilColour supertopics Close Sail exture nona Sails colourE rasion textureErasian This knowledge base contains information classified under different categories called topics These topics may be organised under different topic hierarchies To see the statements defined by a particular topic hierarchy first select the topic hierarchy then click an the statements Button Selected Topic Hierarchy Topic Hierarchies Topic Details Selected Topic Append to Topic Delete Detach Immed 5ubtapics C nil calaur SalTexture Topics in sele
123. cted hierarchy Close Move e nil Calour SailTexture Save Topic Hierarchy Soils colourE rosior as new Kb textureE rosion Topic Statements View T View Topic Hierarchy lew ree Statements Figure 7 77 Topic Hierarchy dialog box Figure 7 76 Topic Hierarchies dialog box Knowledge Acquisition 87 Chapter Seven Software manual for AKT The relevant Topic Hierarchy dialog box Figure 7 77 appears automatically when you highlight a topic hierarchy in the Topic Hierarchies dialog box and is very similar to the Object Hierarchy dialog box explained above see 7 5 2 and compare with Figure 7 29 The Topic Details allows you to see the Topic Details dialog box giving the Boolean Search String that made up the topic hierarchy the search mode for objects and any description that might have been written on the topic hierarchy Topic Statements allows you to see and browse all the statements encompassed in the topic hierarchy View Tree allows you to see the structure of the topic hierarchy 7 12 2 CREATING TOPIC HIERARCHIES In order to create a new topic hierarchy select New in the Topic Hierarchies dialog box see above Figure 7 76 A New Topic Hierarchy dialog box appears Figure 7 78 ee New Topic Hierarchy treefodd se Topic Hierarchy Select a topic to become the new Topic hierarchy m AN Mew topic hierarchy farmers saved Save farmers crop farmers fadder sc
124. cting Trace or Test you can save the new tool both locally to memory or to a disk file by pressing SAVE If you have already saved once before the following message will appear Figure 10 20 me ool Exists ES p ou i Tool already defined do wish to overwrite Figure 10 20 Message that appears when saving a tool for the second time Select Yes Once the tool has been saved select Close If you now go to Tools under the main Tools menu you will find that under User defined tools your new tool is listed as saveStatementsToKb Kb Term 10 5 EDITING TOOLS Only user defined tools can be edited Primitives control structures and systems tools cannot be edited To edit a user defined tool simply enter User defined tools in the Tools dialog box and select the tool in question Select Details You can then freely alter both the tool description and the tool definition However remember to press Save in the Tool Details box to preserve the changes otherwise any alterations will be lost 10 6 DIRECTING TOOL OUTPUT TOA FILE It is possible to direct any tool output to a file rather than to a screen window This is particularly userful for tool outputs larger than 64 Kb which is the limit for screen output In order to do this go to the main Tools menu and select Select tool output mode The program will then allow you to save the tool output in a file of your choice Using Knowledge 144 Chapter Eleven I
125. d this can be recorded here e Methods Here information about the methods used for selecting the interviewees and collecting the knowledge may be described e Location Here information about the exact location of the communities visited can be recorded e Timing of Knowledge Collection The time of year and the season that the knowledge collection was undertaken may influence the knowledge elicitation process and should therefore be noted e General Comments Here any other pertinent pieces of information may be recorded Knowledge Acquisition 78 Chapter Seven Software manual for AKT The Memo dialog box also contains a Topics button which if selected takes the user directly to the Topic Hierarchies dialog box 7 12 below This enables the user to have immediate access to the major subjects of interest in the knowledge base Ri When you open a knowledge base the Memo dialog box will be in Read Only format with the Save button deactivated This is to prevent you inadvertently making changes to the Memo field To reactivate the Save button and to make amendments to the Memo field you must enter it via the Memos option in the main KB menu 7 10 SELECTING SUBSETS OF THE KNOWLEDGE BASE AKT enables the user to extract subsets of a knowledge base according to user specified search criteria Often this selection of subsets of the knowledge base may be a part of the process of evaluating and using the kno
126. d bar will travel down one step in the tool and carry out the instructions on that line the results appearing in the box beneath marked Parameters By the time you have reached the last line the screen will look like this Figure 10 19 me step_dialog BODY oftool saveStatements ToKb Kb Term statements_search treefodd soil _objectall ListFormalStatements statements_save treefodd ListFormalStatements statements_conver numbered treefodd ListFormalStatements TranslatedStatements show This is a numbered natural language version of the statements nl show TranslatedStatements PARAMETERS treefodd soil ListFormalStatements 441 442 451 452 453 454 455 456 457 458 512 513 517 516 527 539 55 TranslatedStatements 441 an increase in rate of erosion of soil causes a decrease in fer Figure 10 19 Using the Step button going though the tool line by line The Trace function allows you to follow the tool step by step and to monitor the actions of each line of the tool The Trace function is enabled only if the tool is syntactically correct Therefore if the tool is not giving the required output it means that one of the individual functions is probably being used incorrectly The step by step facility allows you to determine where it goes wrong by observing the parameter values in the lower box Using Knowledge 142 Chapter Ten Creating your own tools 10 4 4 b The Test button lf you do not wish to test your
127. d for a formal term Type type returns the type of a formal term Type use returns used or unused depending whether term is used by a statement Type values returns list of all the values assigned to an attribute formal term eg formal term treefodd erosion type Type will return Type process formal term treefodd area values Values will return Values decrease increase Parameters This shows the parameters that are required as inputs to the tool and the parameters that the tool uses to return information In the case of the tool formal_term KB Term Type Result the parameters required as inputs are the name of the knowledge base the term the object to be investigated the type of output sought i e attributes or hierarchies The output parameter will be the result i e the attributes or hierarchies sought Using Knowledge 122 Chapter Nine Reasoning with AKT tools In the Tool Definition box the name of the tool and its parameters in brackets are shown The name of the tool must always begin with a lower case letter or be enclosed in single quotes eg JohnsUserTool if it is necessary to use a capital letter for a real name The name of each parameter listed after the tool name must always begin with a capital letter to denote a variable f the parameter is an atom the first letter will either be in lower case e g soi or it will be enclosed in single quotes for proper names
128. d more useful than the above statements As a result of the interpretation involved different sets of statements will be abstracted from the same source knowledge by different people with different objectives It is important to realise that any abstraction of knowledge for representation in the knowledge base is open to debate There can be no single correct abstraction although there can certainly be incorrect Tutorials 156 Chapter Fourteen Tutorial in creating a simple knowledge base ones The statements in Table 14 1 are an example of one set of statements abstracted from the text These do not immediately and literally relate to the source knowledge but are designed to capture its ecological content Some statements are speculative and demand validation while others can be expressed with more confidence Table 14 1 Example set of statements abstracted from the text Burning causes a decrease in numbers of pests Burning causes a decrease in crop disease levels Clearing causes an increase in soil temperature An increase in soil temperature causes an increase in the rate of decomposition of organic matter Nutrient availability is high for two years after burning Harvesting causes a reduction in soil nutrient levels Leaching causes a reduction in soil nutrient levels A reduction in soil nutrient levels causes a reduction in soil fertility An increase in weed density causes a decrease in crop yield Soil erosion is not a problem
129. dge held by different groups of community members Methodology 49 Chapter Seven Software manual for AKT CHAPTER SEVEN SOFTWARE MANUAL FOR AKT Ri To install AKT5 onto your computer read How to Install AKT5 at the front of this manual 7 1 INTRODUCTION AKT provides an environment for the creation of a knowledge base by allowing you to enter view and edit knowledge as well as enabling automated reasoning with the contents of the knowledge bases created Each knowledge base created with AKT includes the following information e theunitary statements e source details for each statement e lists of formal terms their definitions and synonyms e memos on individual sources individual statements and the knowledge base as a whole e records of any object hierarchies developed e records of any topics and topic hierarchies developed e full information about the structure and content of any diagram sets in the knowledge base Each knowledge base created is stored as a set of Prolog facts and is managed via the KB menu Figure 7 3 below 7 2 GETTING STARTED On opening AKT the first image will be the title page below Figure 7 1 Note the version number that Agroforestry Knowledge Toolkit you are using for Vvindows ART Version 5 00 When registering any queries about your knowledge base with technical support in Bangor email akt5 bangor ac uk you must state the version num
130. e In order to get a complete picture of the interactions between the different nodes the Zoom Out button will reduce the diagram as in Figure 8 5 Figure 8 5 The reduced diagram of the soil kb knowledge base using Zoom Out In order to enlarge the image again Zoom In is selected There are four zoom levels with ratios of 1 1 2 1 4 1 and 7 1 Knowledge Acquisition 97 Chapter Eight The diagram interface 8 2 3 6 Centre zoom It is possible to recentre and magnify the diagram instantly by selecting Centre Zoom and then placing the mouse pointer over the node you wish to appear in the centre of the diagram and clicking once with the left mouse button 8 2 4 LABELLING 8 2 4 a causes1way causes2way labelling A diagram can be presented in three forms The simplest form is as the diagram above Figure 8 2 where only the link and nodes are drawn By clicking on the Label Mode once the diagram changes to Figure 8 6 The 1 or 2 beside the links indicates whether the link is a causes1way or causes2way causal statement The T arrow indicates an increase whilst the arrow indicates a decrease Where something else other than an increase or decrease of the first node causes an increase or decrease in second node this is indicated by a dot es aff farm jah priwate fodder rainfall System firewood availability availability frequency season Scarcity Aiea he le 2 sb scale rainfall farmer
131. e are using the Atwima knowledge base a knowledge base created to explore farmers knowledge on soil fertility management soil classification weed management and cocoa shade trees in the Atwima district of Ghana mae started Load the AKT program 5 0 onto your computer follow the instructions How to Install AKT 5 at the front of the manual 2 Load the file atwima kb onto your computer 3 Open the AKT program 4 Press OK on the first screen and the main menu will appear with the options at the top left hand corner 5 Select KB Open Kb atwima kb 6 Press OK at the various messages that appear until the Welcome dialog box appears Welcome Dialog Box Read the Welcome dialog box to get an idea what the knowledge base is about Press Further Details for further details about the knowledge base Press Close on each dialog box when you have finished reading the dialog boxes Press Topics Then highlight in turn each topic hierarchy listed in the Topic Hierarchies dialog box You will see in each new Topic Hierarchy dialog box that appears all the topics which that particular topic hierarchy covers For example the topic hierarchy Fallows contains the topics fallow length fallows fallows and soil types and allows on fertility Question what topics does the topic hierarchy Weeds cover Press Close on both dialog boxes to return to the Welcome Memo and Close again to arrive at the
132. e as the output at completion of the tool Parsimonious Restricting formal terms used in the knowledge base to the minimum possible without losing the meaning of the knowledge captured Primitive Small program segments within AKT employed for running a tool Prolog WinProlog An artificial intelligence programming language used for developing AKT software Scientific knowledge Knowledge generated in a formal manner by universities research and other institutions Task language A dedicated procedural programming environment in AKT software which allows users to build tools or programmes using primitives and control structures to interrogate a knowledge base Tool A small computer program either supplied with AKT software or developed by the user using primitives control structures and pre existing tools for interrogation and reasoning with a knowledge base Tractable Easily managed malleable Unitary Statement The smallest useful unit of knowledge which can stand alone without reference to other statements to be comprehensible WinAKT Windows version of the Agroforestry Knowledge Toolkit the former name of AKT 168 BIBLIOGRAPHY Bandy D E Garrity D P amp Sanchez P A 1993 The worldwide problem of slash and burn agriculture Agroforestry Today 5 3 2 6 Bell J Hardiman R J 1989 The Third Role the naturalistic knowledge engineer Knowledge elicitation Principles techniques and applications ed
133. e cece ee eeeeeeeeseeeenesaeeens 1 7 3 b Causal Glagramimin sc c 255 oto sie doeet e qe bebes eked enascutes CHAPTER TWO KNOWLEDGE ELICITATION eese 2 1 DESIGNING A KNOWLEDGE ELICITATION STRATEGY eeeeeeese 2 1 1 A FRAMEWORK FOR DESIGNING A KNOWLEDGE ELICITATION RAT EG Y carteri exitus s Basado de o OR euEx S ox eini cena PO Eng em GE 2 1 4 d SCOPING sicher oEs cust Trousers Deo et rr NEMPE MDC ORAE 2 1 1 b Definition of The dOMAIN cece cece cece ee ee eeeeeeeneas 2 1 1 c CombpllallQDiz e s iso oer aa tunes est et E EN EE URS EY ee 2 1 10 etieraliSallOli iiec oan dne oua iens ura edens 21 2 SAMPLE SIZE EPI Ehe deese N Ap Oo E oU aM 2 2 CONSTRAINTS UPON KNOWLEDGE ELICITATION eese 2 9 INTERVIEW TECHNIQUE saint tiii Per HER en aS ado adu d Ende s 2 3 1 SOME GOLDEN RULES FOR INTERVIEW TECHNIQUES CHAPTER THREE PREPARATION FOR KNOWLEDGE BASE CREATION One jIPREPARA uM e Mr 3 1 1 SPECIFICATION OP OBJECTIVES 593 ie ec aa A 3 1 2 BOUNDARIES OF THE KNOWLEDGE BASE ccc cece eee CHAPTER FOUR KNOWLEDGE REPRESENTATION sese 41 ABSTRACTING KNOW LEDGE 2 cudccuisticceie eee a T 4 1 1 BASIC CONCEPT Orriu at osdatu ie a a E TA 4 1 2 UNITARY STATEMENTS AS BASIC UNITS OF KNOWLEDGE 4 1 3 RECORDING THE CONTEXT OF A STATEMENT Nor MEG eg SO RR EET ETT Mm ATD
134. e dependent not only on the increase of pest numbers but also on economic constraints such as affordability availability and time and thus an action will rarely simply be an effect of an ecological state alone 4 2 4 c Comparison statements Comparison statements compare the relative value of a pair of objects The formalised comparison statement takes the following form comparison Attribute Object1 Comparison type Object2 Comparison statements may be self evident for example Bamboo grows faster than fruit trees Frequently however comparison is implicit usually against an implicit norm The unitary statement Bans leaves decompose slowly can be interpreted as being a comparison with the average rate of leaf decomposition This kind of implicit comparison is however best captured as an attribute value statement in this case att value process part bans leaf decomposition rate slow The only instances in which implicit comparison may best be represented as comparative statements are those in which there are clearly only two possible circumstances So for example the statement Forests with closed canopies cast deeper shade is a genuinely comparative statement and might be more explicitly stated as Unitary statement Forests with closed canopies cast more shade than forests with open canopies Methodology 28 Chapter Four Knowledge representation Formal statement comparison depth of shade c
135. e focused knowledge bases in their own right Search strings aliases may be converted into topics which are groups of related search strings amalgamated into one topic string using Boolean connectives for example cattle OR sheep AND grass The Welcome memo that appears on loading a knowledge base provides direct access to the topics so that a new user may see immediately what sort of information is in the knowledge base and have a means of accessing it 1 4 2 DIAGRAM INTERFACE A diagram based interface for knowledge representation and retrieval is also available within AKT to support the viewing of statements and the links between them For most new users the diagram interface also serves as the first mode of entry in recording knowledge A diagramming approach to representing information about agro ecosystems is familiar to many resource managers and provides an intuitive means of synthesising and representing complex information It has also been used successfully in cross cultural situations to form a clear consensus about the important causes of land use problems Lightfoot et al 1989 and in enabling articulation of local knowledge Conway 1989 Thus it has been shown that diagrams in knowledge elicitation can result in a set of knowledge that is significantly more comprehensive and coherent than that which results from other approaches to elicitation Producing a diagram is also a powerful means of enabling the develop
136. e formal term crops Boolean searches using and and or or 7 10 1 a Boolean searches can include combinations of formal terms linked with and and or or Try it out on the formal terms pests and disease Select Boolean Search from the main KB menu From the Display Kb terms of type drop down menu select object From the list of objects displayed highlight pests and press Select The term pests will appear in the Boolean Search String at the bottom of the dialog box 10 Press the OR button from the Boolean Options box 11 Now find the term disease highlight it and press Select 12 In the Boolean Search String at the bottom of the dialog box should be pests or disease Now press Search 13 You will be presented with all the statements in your knowledge base containing either the term disease or the term pests 14 If you repeat this process but select the term AND instead of OR no statements will be found as there are no statements in the knowledge base which contain both the term disease and the term pests 2 gt gt When undertaking searches combining and and or it is necessary to use brackets as one does in algebra to give the order of precedence in the search Experiment with burning and pests or burning and disease To get all the statements mentioning either burning and pests or burning and di
137. e hierarchy plants or select an object from the KB objects list to act as the hierarchy name 4 Press Save The hierarchy name plants now appears in the Object Hierarchies list in the Object Hierarchies dialog box K Appending objects to the object hierarchy Highlight the name of your new Object Hierarchy 2 In the Selected Object box press Append to A list of all the objects in the knowledge base then appears 3 Select vegetation 4 Press Append The formal term vegetation then appears in the object hierarchy plants as an immediate sub object of plants Building up object hierarchies 7 5 3 Add the following statements to your knowledge base Beans fix nitrogen Corn does not fix nitrogen Rice does not fix nitrogen Now practise creating another level in the plants object hierarchy 1 Highlight vegetation so that it appears in the Object box of the Hierarchy Structure section 2 Press Append To 3 In the Append Object dialog box select crops from the Objects list and press Append 4 You now have an object hierarchy in which the formal term vegetation has the parent plants and the child crops Tutorials 162 Chapter Fourteen Tutorial in creating a simple knowledge base 5 Try incorporating beans corn and rice in the object hierarchy plants as subobjects of crops
138. e only diagram to appear will be the diagram for the whole knowledge base generated afresh Fi By selecting Delete Diagram or Delete All Diagrams you are NOT deleting the statements from the knowledge base Only if you delete an individual node link from the diagram do you delete the equivalent statement from the knowledge base 8 8 CREATING NEW DIAGRAMS Before creating a new diagram it is necessary to have loaded a knowledge base Therefore select KB from the opening menu and create a new knowledge base by selecting New KB and giving the new knowledge base a name Selecting Show KB Diagrams from the main Diagram menu Figure 8 1 will give you a blank diagram screen Figure 8 21 because there is not yet any information in the knowledge base Knowledge Acquisition 111 Chapter Eight The diagram interface gg AKT current knowledge base New File KB Diagram Tools Help Diagram of the complete New knowledge base all C cause C link copy to Clipboa Memo Zoom In Object Zoom Out Attribute Centre Zoom Process Label Mode Refresh BEER Action Undo I a fen Link ia Show Paths Print Window Delete Node Link Navigate f Statements TULLIA r Hide Causes Effects 4 Causes Effects m Select Diagram Node Link i E m Show Hide Label i E B Figure 8 21 The empty Diagram Screen
139. e tools defined in this way can also be incorporated into more complicated tools so allowing complex tasks to be completed automatically Ri These task definitions are similar to the idea of macros used in other computer applications 9 1 1 WHAT ISATOOL A tool is created by writing a definition A definition is a set of functions linked with appropriate punctuation and control structures and entered into the definition field A function calls the underlying program code to perform a specified task Some functions are part of inference mechanisms that undertake automated reasoning tasks on the knowledge base others are concerned with the management of inputs and outputs interfacing to and from inference mechanisms Functions are defined by a name one or more arguments variables associated with it 9 1 2 WHAT DO THE TOOLS DO he task language allows the user to interrogate the knowledge base and carry out assessments of the knowledge it contains These can be simple queries such as How many conditional statements are there How many statements are not represented in the diagram What comparison statements are there or a more sophisticated analysis of the knowledge base for example What are the immediate causes of soil erosion What are all the effects of shading Using hierarchical information which livestock are suitable for small landholdings 9 1 2 a What is a primitive Primitives are small program segment
140. ecific terms that form part of the formal language This linkage and ordering provides information on the way in which the elements of the statement are related and therefore enables a semantic interpretation of the syntax of the statement The formal grammar that provides the basis for formal representation is stated in Table 4 1 A summary explanation of the grammar is provided in this section and a more detailed exploration of its application follows Methodology 21 Chapter Four Knowledge representation Table 4 1 The definite clause grammar Terms in bold are reserved terms in the grammar I e words reserved for use by the system terms starting with a capital letter are variables gt means can take the form of FormalSentence gt Statement if FormalConditions FormalSentence Statement Statement Cause Causes Effect where Causes is an element of the set causes1way causes2way Statement AttributeStatement Statement gt not AttributeStatement Statement gt link influence Thing Thing Statement gt link Link Object Object Statement gt link Link ProcessBit ProcessBit Statement gt link Link ProcessBit Object Statement gt comparison Attribute Object Comparison Object FormalConditions FormalConditions and FormalConditions FormalConditions FormalConditions or FormalConditions FormalConditions Statement FormalConditions ActionBit FormalConditions ProcessBit AttributeStatement gt
141. eck and then go on to c For c we need the Statement primitive statements_convert Mode Kb Original Converted Enter the primtive details via the Browse Tools and copy and paste the tool name and parameters as above in a Then add a comma and press carriage return The growing primitive should now look like this statements search Kb Term object all ListFormalStatements statements save Kb ListFormalStatements statements convert Mode Kb Original Converted The description box below suggests ways in which the primitive statements convert Mode Kb Original Converted might be modified Allows user to change the format of either a single or a list of statements The choices are a Mode formal Convert list of statement identifiers to a list of formal statements b Mode identifier Convert list of formal statements to a list of statement identifiers c Mode translate Translate a list of formal statements to their natural language equivalents d Mode numbered Convert list of statement identifiers or formal statements to numbered list of natural language equivalents eg statements convert formal soil 1 25 73 FormalStatements statements convert identifier soil att value black soil fertility high Number statements convert translate soil att_value black_soil fertility high Translation statements convert numbered soil att value black soil fertility high Numbered NOTE when converting formal statements to their equiv
142. ect hierarchies and application of the formal grammar respectively However while the mechanisms for creating glossaries and hierarchies are straightforward the management of hierarchies and glossaries is a demanding task The consistent use of terms has a profound impact on the utility of the resulting knowledge base particularly in relation to the use of automated reasoning tools The consistent use of terms is facilitated by e minimising the number of object attribute process action value and link terms used e ensuring the consistent use of values for attributes and e providing definitions for each term such that their use is transparent and can be assessed by the knowledge base developer or other users The creation of object hierarchies makes further demands Sets of objects can be hierarchically classified in many different ways for different purposes Indeed it may not be possible to develop a single classification of a set of objects that is appropriate for all the intended uses of a knowledge base For that reason it is possible for an object to appear in several hierarchies although it is not possible for an object to appear more than once in the same hierarchy 4 4 DIAGRAM BASED REPRESENTATION 4 4 1 INTRODUCTION The representation of knowledge as a diagram provides a powerful means of helping to ensure that the knowledge set that is represented is comprehensive and coherent and therefore useful The diagramming approac
143. ects of a particular statement a message will appear to inform you of the fact Knowledge Acquisition 63 Chapter Seven Software manual for AKT If you highlight a statement and press Navigate it will give you a diagram of the immediate causes and effects of the selected statement from which you can build up the diagram further from within the diagram interface Diagrammatic representation is dealt with in detail in Chapter 8 7 4 6 SORTING STATEMENTS IN THE STATEMENT CARD The statements in the statement card can be sorted either numerically or by type attribute causal comparison or link statements When you open a knowledge base or create a new one the statements will be listed numerically To list them by statement type press the Sort by Category button at the top of the statement card see above Figure 7 6 f the statements are sorted by category the button changes to Sort Numerically 7 4 7 INVERSE STATEMENTS AND NUMBERING Each two way causal statement i e those using causes2way generates an invisible inverse statement a statement that is used in reasoning but is not displayed on the screen see above Chapter 4 2 4 a Each time a knowledge base is loaded all statements are renumbered from 1 to the total number of statements The inverse statements are then generated and added to the knowledge base with numbers following on from the visible statements For this reason when you begin adding new statements to a knowledge
144. ed As with the specification of objectives the specification of boundaries may be iterative Initial acquisition of knowledge related to tree fodder demonstrated that while these three topics merited consideration much basic understanding was common to all of them The knowledge base boundaries were therefore modified by merging the three knowledge bases By identifying the boundaries of the knowledge base one automatically sets the specifications upon which the knowledge elicitation strategy can be based Key points of Chapter Three Preparation before actually developing a knowledge base involves two crucial activities Specifying objectives of creating a knowledge base Defining scope and boundary of the knowledge base The purpose of the knowledge base should define the objectives not any preconceived specification of the structure and contents of the knowledge base As a knowledge base develops both the objectives and the boundaries can be redefined Methodology 18 Chapter Four Knowledge representation CHAPTER FOUR KNOWLEDGE REPRESENTATION This part of the manual describes the process of knowledge representation Knowledge representation comprises e the process of abstracting knowledge e the process of formal representation e the process of formal term specification 4 1 ABSTRACTING KNOWLEDGE 4 1 1 BASIC CONCEPTS The knowledge given by an informant is made up of a combination of basic units of knowledge
145. ed objects into object hierarchies These capture both local and scientific classification of things and allow you to apply order sorted logic techniques in reasoning Robertson et al 1991 By careful management of the content of the lists of formal terms and object hierarchies you can ensure consistent use of terminology across the knowledge base Consistent and parsimonious use of terminology greatly improves the subsequent performance of inference mechanisms as well as improving the ease with which your knowledge base can be understood by other people The lists of formal terms and object hierarchies also provide a framework for use of familiar database type functions Sets of statements can be abstracted from the knowledge base by searching the formal statements using combinations of any of the formal terms sources aliases and topics There are three possible search strategies in relation to objects searching for just one selected object searching for a selected object and all objects below it Formal representation of unitary statements is explained step by step in Chapter 4 A parser is a computer program that checks the syntax of a statement to ensure that it conforms to a defined grammar Methodology 4 Chapter One Overview in an object hierarchy or searching for objects both above and below the selected object in an object hierarchy In this way you can abstract sub sets of the knowledge base which can then be treated as mor
146. edge 140 Chapter Ten Creating your own tools Tool Details sawe Statements Tok b Kb Term Tool user defined Current Tool new Description This tool collects all statements relating ta a user specified term ar terms and then saves them as a new knowledge base Paramete Input Tool Detinition Tool Name Parameters ovntax Check savectatements T aKhiKb Term 1 _Browse Tools Tool Body Note Musttinish with a full stop then a new line __Print Tool selection of user defined statements and saved as a new Eb statements search Eb Term object all ListFormalstatements statements saverEb ListFormalStatementz ofp info for user statements convert numbered Eb ListFormalStatements Translateds Show This is a numbered natural language version of the statem shawiTranslatedStatrementz Figure 10 15 The new tool saveStatements TOKB Kb Term completed Then press Save A dialog box will appear Figure 10 16 with the two parameters in the toolname requesting you to specify which are the input parameters In this case both parameters are input parameters so tick the two and then press OK Eg Confirm input parameter s xX Testor Trace Kb Iv Input Figure 10 16 Dialog box requesting the input parameters 10 4 4 TRACING AND TESTING A NEW TOOL Once a new tool has been created it is important to test whether it works properly This can be done by using either Trace to step through the to
147. edge base through the combination of two or more existing knowledge bases for example knowledge in the same domain but from different sets of sources In principle the combination of two knowledge bases is a straightforward task The process of merging knowledge bases is essentially one of ensuring consistency of terminology Although effective software support for merging knowledge bases is available the process is demanding for two reasons In the first place two knowledge bases in the same domain are unlikely to use precisely the same terminology especially where created by different knowledge base developers Although many equivalent terms for example alternative names for the same species can be identified without difficulty equivalence for other terms is much more problematic and even where definitions of terms are provided can only be resolved through reference to the original knowledge base developer As a result it is doubtful that consistent use of terminology across knowledge bases is practically possible unless strict protocols for the use of terminology in the creation of the knowledge bases in the first instance are developed and applied A further problem is encountered where the content of the knowledge bases to be merged has been previously formally represented The process of formal representation involves many decisions about the most appropriate approach to representation When this process has been undertaken by differen
148. edge elicitation is the process whereby selected informants are encouraged to articulate their knowledge This is normally done through repeated interviews with farmers and domain experts Knowledge can also be abstracted from written material Creation of unitary statements is the process of extracting knowledge from the text or interview material and breaking it down into simple statements each containing one unit of knowledge These unitary statements form the intermediate stage between knowledge articulation and representation Methodology 2 Chapter One Overview Formal representation is the process of coding knowledge for input into a computer using a restricted syntax as defined by a formal grammar developed for the purpose Formal representation results in statements with which you can reason automatically using computer software Formal Term Keyword specification is the process of identifying and organising key components of knowledge Formal terms in AKT are either objects e g pests crops field processes e g erosion infiltration growth actions e g pruning harvesting planting attributes e g rate of erosion pest population size tree height values e g 3 m 10 t ha high low or links user defined e g eat as in cows eat grass pollinate as in fruit bats pollinate Parkia biglobosa
149. eeeeaees 7 3 1 STARTING ON A NEW KNOWLEDGE BASE eese 7 3 2 OPENING AN EXISTING KNOWLEDGE BASE esee 71 4 ENTERING KNOWLEDGE THROUGH THE STATEMENT INTERFACE 7 4 1 ENTERING SOURCE INFORMATION seen TANG New SOUNCES cene heh ane ortis d e REOR UNDA S LL D qx vds Redes 7 4 1 6 Sources already entered ccc cece ees eeeeeeeeeeeeeeeeeaas 7 4 2 ENTERING A NEW STATEMENT ccc cece cece cence eeneee eens 7 4 3 EDITING A STATEMENT 4eteotsuobs i op AE aset net tub RUPES 7 4 3 a Adding definitions to formal terms 7 4 3 6 Appending or detaching additional sources 7 4 3 6 Appending memos sesssssssseeeen se mne nnn nn 7 4 4 DELETING A STATEMENT iios tio Ante E hObEP EEUU Mr UBUUpISE 1 9 7 6 1 1 7 8 7 9 7 10 7 11 7 12 7 13 8 1 8 3 1 4 5 1 4 6 1 4 1 7 5 1 CREATING OBJECT HIERARCHIES cessere 7 5 2 VIEWING OBJECT HIERARCHIES ccc cece cece cence nena ee eeneees 1 5 3 BUILDING EDITING OBJECT HIERARCHIES looa Adding DISCS isa dact i bee Pape bee ooa e eva e pasa bu Bob fad oe dosis 7 5 3 D Detaching ODJecls i i ibo bere ER REED sente E Ee DER Et 7 5 3 Moving objects within a hierarchy ccc cece eee ee ee eaes 7 5 3 d Copying objects between hierarchies
150. eld until recently that drop size was independent of canopy morphology Brandt 1989 Thornes 1989 Scientific understanding of how leaves of different types affected drop size was revised and brought in line with that of the Nepalese farmers in 1993 when new instrumentation allowed more reliable measurement of drop size Hall and Calder 1993 The key point here is that once researchers were made aware that tree crop interactions were important to farmers and that farmers had a cogent interest in minimizing negative impacts of trees on soils and crops they could see the relevance to farmers of research in this area and had the terminology to communicate with farmers about it In the last few years researchers at frontline agricultural research institutions serving the eastern mid hills have done work directly on tree crop interactions Joshi and Devkota 1996 and there are now plans for tree crop interactions to form a central basis of agroforestry research in the Western Development Region Paudel et al 1997 1 7 1 THE EXPRESSIVENESS OF THE AKT APPROACH AND IMPLEMENTATION The formal grammar has proved effective in capturing a significant proportion of the description of an agro ecosystem as given by farmers see Box 2 It was designed as a means of capturing qualitative descriptions of components of the agro ecosystem and the ecological relationship between these components rather than capturing technical knowledge about the management of
151. elopment institutes are often inadequate Walker et al 1997 The methodology outlined in this manual has been designed to allow the evaluation and use of complex qualitative information about agroforestry practices It has been developed with a particular emphasis on the local knowledge of farming communities in developing countries It provides an approach to decision support in planning agroforestry research and extension activities which is appropriate to the nature of existing knowledge The AKT software provides an environment for knowledge acquisition in order to create knowledge bases from a range of sources Database functions and a graphical user interface allow flexible exploration retrieval and evaluation of the knowledge More powerful means of retrieving information from Methodology 1 Chapter One Overview knowledge bases by using automated reasoning techniques widely used in the field of artificial intelligence are also available A task language allows more advanced users to make their own reasoning tools appropriate to their particular decision support tasks by customising the existing tools or by writing new tools 1 2 WHAT DO WE MEAN BY KNOWLEDGE To define knowledge is to enter a philosophical minefield but in order to work with AKT we must state explicitly what we mean by knowledge in this context For the purposes of AKT we define knowledge as the outcome of the interpretation of data independent of the in
152. emanded Unambiguous representation depends on e complete specification of the meaning of a unitary statement e complete representation of the context of application of the unitary statement and e precise use of terms within that unitary statement 5 2 3 a Complete specification of meaning Unitary statements may frequently contain an implied meaning Even where it can be assumed that this is understood by potential users of the knowledge base it may significantly constrain automated reasoning For instance while it might be valid to assume that users understand that the statement in a knowledge base about tree fodder Celtis australis leaves can cause sickness means that feeding the leaves to livestock may cause sickness in livestock automated reasoning will not pick up this implication Even simple reasoning such as answering the question What is the consequence of feeding Celtis australis leaves to goats cannot therefore be automated As a result formal representation must state explicitly any implied meaning in this case maybe as action feeding part Celtis australis leaves livestock causes 1way att value livestock health decrease Methodology 40 Chapter Five Knowledge base management 5 2 3 b Context of application Knowledge is inescapably contextual at some level even though the AKT approach to knowledge base creation is based on the disaggregation of sets of unitary statements Recording cond
153. ems tools and control structures provided to carry out tasks not previously envisaged by the programmers Once defined user tools themselves can be used as primitives to create larger tools This chapter looks at tools and the mechanics behind the primitives and systems tools Chapter 10 looks at user tools and teaches you how to create your own 9 2 WORKING WITH TOOLS To display the tools provided select Tools from the main Tools menu Then from the drop down menu select the type of tool you want Control structures Primitives System tools User tools 9 2 1 PRIMITIVES 9 2 1 a Opening primitives In order to work with primitives select primitives from the drop down menu When primitives has been selected another drop down menu appears listing the types of primitives available Figure 9 1 ER Cause and Effect Display Formal Term Hierarchies Miscellaneous SOURCES Statement Test List d Figure 9 1 Drop down menu for primitives Using Knowledge 120 Chapter Nine Reasoning with AKT tools 9 2 1 6 Different categories of primitives The following is an explanation of the different categories of primitive available Cause and Effect Functions for the extraction of information about all types of nodes and the pathways between them Display Functions that allow the user to display the results of running a tool in a text window in various ways Also allows tools to display messag
154. er to synthesise available knowledge on a particular topic and as a result to increase his or her understanding of that topic Diagrams can be used to make an explicit statement of what is known about the topic Furthermore it enables developers to assess the completeness of their current understanding or of the available knowledge through the identification of missing linkages in the diagram The facility for diagram generation provided within AKT see Chapter 8 is a powerful tool in this respect The diagramming interface uses a restricted syntax such that two nodes with a link between them is equivalent to a unitary statement The two nodes and link are parsed to create both a formal representation of the unitary statement and a natural language equivalent Figure 1 3 illustrates the correspondence between two nodes with a link and a formal unitary statement In this way you can add to a knowledge base without learning the formal grammar A range of tools provides a flexible diagramming environment The ability to develop hierarchically linked sets of diagrams overcomes the space limitations which can be associated with a diagramming approach Increase causes increase att value leaf size increase causes att value tapkan drop size increase An increase in leaf size causes an increase in Tapkan drop size Figure 1 3 Correspondence between the content of a diagram and natural language and formal statements The diagram syntax d
155. erent sections of the knowledge base This is particularly useful in large knowledge bases where a diagram can show a subset of the knowledge base such as a particular topic or a set of statements that are of interest see section 8 3 below A diagram represents a particular view of the internal knowledge base There can be many views co existing showing differing aspects of the knowledge It is important to remember however that if you add or delete nodes and links from any diagram the knowledge base will reflect that change The knowledge base and any views of that knowledge will always be consistent 8 2 VIEWING A DIAGRAM The diagram menu Figure 8 1 shows the options available in the diagram interface Eg AKT current knowledge base treefodd File KB Diagram Tools Help show Kb Diagrams Hide Diagrams Copy diagram cave Diagram as New Kb Delete Diagram Delete All Diagrams Pants Figure 8 1 The main Diagram menu If you are working on a new knowledge base Show Kb Diagrams will give you a blank screen on which you can begin to create a knowledge base from scratch using the diagram functions For creating a new diagram see 8 8 If you are working on a previously created knowledge base where no sub diagrams have been developed previously then the Select Diagram dialog box will not appear instead the program will automatically generate a diagram for the complete knowledge base Figure 8 2 See 8 3 4 for viewing
156. erness varied in a large number of tree species throughout the season This demonstrates complementarity between farmers and scientists knowledge that could be exploited in designing appropriate research farmers understanding of intraspecies variability has already led researchers to revise strategies for sampling tree material for analysis of nutritive value Clearly because of complementarity the combination of what farmers and scientists know represents a more powerful resource than either knowledge system alone Box 4 Identification of leverage points by comparison of what farmers do with what they know Continuing the unfolding example related to Nepalese hill farming used in Boxes 1 3 in addition to documenting farmers and researchers knowledge a detailed tree inventory was conducted permitting comparison of what farmers said about trees and how they actually incorporated them into their farming systems Thapa 1994 Statistical analysis of the location of trees that farmers classified as malilo and rukho showed that farmers had a higher proportion of malilo trees growing in association with crops than rukho trees consistent with malilo trees being considered less competitive with crops and enhancing soil fertility In contrast nearly half of the trees that farmers had which they classified as causing heavy tapkan were grown on crop terrace risers where according to local knowledge they would reduce crop yield and promote
157. es loaded weevil and soil appear in the Files list To change the current knowledge base highlight one of the knowledge bases in the Files list and press OK The selected knowledge base will now automatically become the current knowledge base Knowledge Acquisition 93 Chapter Eight The diagram interface CHAPTER EIGHT THE DIAGRAM INTERFACE 8 1 INTRODUCTION The diagram interface serves a number of purposes It provides a means of easily entering knowledge into the knowledge base as diagrammatic linked sets of unitary statements It also gives a pictorial view of the unitary statements entered into the knowledge base via the statement interface and it provides a number of functions to manipulate and organise the knowledge represented in the diagram Whenever a new statement is added by joining two diagram nodes with a link a corresponding formal language unitary statement and its natural language equivalent are generated in the knowledge base Equally whenever a causal or link statement is entered into the knowledge base via the statement dialog any relevant diagrams are automatically updated to include the new statement Only causal or link statements including conditional statements can appear in diagrammatic form The system will generate a complete diagram of the whole knowledge base i e one that includes all the causal and link statements However it is possible to build up a set of diagrams showing diff
158. es and request input from the user Functions for the manipulation of formal terms Hierarchies Functions for extracting information about objects within object hierarchies List Provide a variety of functions for operating on lists such as sorting appending and combining lists Miscellaneous These are assorted primitives that do not fall into any of the above categories Function for examining the details of any sources in the knowledge base Functions that operate on statements Allows searching and manipulation of any statements which exist within the AKT environment Functions that allow rue false checks to be made and a way of aborting the running of a tool Generally primitives are not run in isolation but are used within tools Some primitives however can be run independently and give useful results All primitives and system tools have individual descriptions of their functions and parameters together with an example of their use available via the Details button on the category dialog box A full list of the tools including the same details as above are also available via the Help ToolList menu This list incorporates all primitives system and any user tools 9 2 1 c Understanding the Details box In order to demonstrate the Tool Details dialog box we have selected a primitive formal term KB Term Type Result from the Formal Term category of primitives Click on this tool and the tool details will automatically appea
159. es on their farms or the integration of agricultural activities in forests As such agroforestry practices have multiple objectives and components and are characterised by their complexity In recent years agroforestry has received considerable attention from people working to foster sustainable and equitable land use in the developing world Because agroforestry practices are generally complex effective decision making in research and extension depends upon making effective use of all available knowledge Increasingly development professionals recognise the value of augmenting scientific and professional understanding with knowledge held by local people Brokensha et al 1980 Warren et al 1995 Sinclair and Walker 1999 This knowledge is of particular interest but is often incomplete or contentious and different knowledge sources though complementary may not be immediately compatible or comparable Moreover much of the information about the ecology of agroforestry practices is qualitative and may include observational information such as qualitative correlations or be descriptive Precise environmental data and quantitative models are rarely available In order to combine local scientific and professional knowledge effective mechanisms are needed for accessing recording evaluating and synthesising knowledge on specified topics from these sources Existing mechanisms for doing this as they are currently applied in research and dev
160. esearch planning and prioritisation by identifying key gaps in understanding that constrain the productivity stability and sustainability of an agroecosystem The formal grammar balances three competing needs e the need for an expressive grammar which allows a significant proportion of ecological knowledge about agroforestry to be represented e the need for a simple grammar which can be successfully applied by users with only limited training and e the need for a flexible grammar which can be combined with a range of appropriate inference mechanisms to automate reasoning tasks To maximize flexibility a task language is provided within AKT which is designed to allow you to customize reasoning tasks This may be done by adapting existing tools to suit your particular needs or by creating completely new tools the need for which was not envisaged by the software development team 1 6 APPLICATION OF THE KNOWLEDGE BASED SYSTEMS APPROACH TO AGROFORESTRY RESEARCH AND EXTENSION To date knowledge bases have been created in conjunction with agroforestry research programmes in Nepal Sri Lanka Thailand Tanzania and India Indonesia and Kenya Users may be researchers or extension workers though the system is most powerful where there is an institutional investment in making better use of qualitative information The system currently being used in a range of applications by governmental and non governmental organisations around the world
161. esponse true or false f the response is true then Q a primitive tool or a combination of both is invoked before continuing with the next primitive in the tool definition If the response is fa se then Q is ignored and the tool continues with the next primitive in the definition If then else P Q R It is possible to elaborate on the above tool by using the if then else control structure This is similar to the if then structure except that if the test fails the else call is implemented rather than simply exiting the control structure tool Repeat until Call Test This control structure enables you to repeat a Call ie an instruction or chain of instructions until a Test is successful Using Knowledge 124 Chapter Nine Reasoning with AKT tools Test each in list for Element List Goal This control structure tests each item in a list Passes Fails for a specified condition and returns two lists one containing the items that meet the condition and one containing the items that do not meet the condition a call is goal consisting of an instruction or a sequence of instructions where an instruction can be a primitive or system or user tool 9 3 SYSTEM TOOLS System tools are the tools already created and supplied within the AKT program If you select System Tools from the Tools dialog box the following drop down menu appears Figure 9 6 rmt Control structures Frim
162. ess Unitary statement Formal statement Siris has small leaves att value part Siris leaf size small Sirius does not have big leaves not att_value part Siris leaf size big These statements may also occur within causal statements For example TUA capital letter is used for this argument of the att value clause to denote a variable Methodology 26 Chapter Four Knowledge representation Unitary statement Formal statement The small leaf size of Siris causes a low att value part Siris leaf shading effect size small causes 1way att_value process shading effect low 4 2 4 6 Causal statements Given that a causal statement takes the general structure X causes Y Y will usually be a change in the value of an attribute This change can be captured by using one of the special values increase decrease change or no change X may also be a change in the value of an attribute again taking one of the four special values or may be a process or an action The grammar also allows objects to be a cause for example sheep cause soil creep but this is incomplete containing implicit information The complete statement for example trampling by sheep causes soil creep is always preferable but the feature is retained in the grammar for cases in which it is not known how an object causes a change but simply that something about its presence does Thus a causal statement can take one of
163. estock Detach Immediate SubO bjects Move Copy View Tree Figure 7 29 Object Hierarchy dialog box aas Object Hierarchy treefodd_kb KB Name treefadd BICI Beccles Obes Objects in Hierarchy Hierarchy Structure Super byeacts Close Object Details Selected object Append to small animal Detach Move Copy View Tree Figure 7 30 Highlighting large_animal in the Object box of the hierarchy structure To get a comprehensive view of the Livestock hierarchy structure select View Tree The following diagram appears Figure 7 31 the scroll bars enabling you to view the whole diagram It is also possible to copy the hierarchy tree and paste it to another package by pressing the Copy to Clipboard button Open the package and paste the hierarchy tree immediately by selecting Edit and then Paste or by pressing Ctrl v ee Hierarchy treefodd kb Name treetadd Hierarchy Livestock Tree animal large anirnal buffala cattle small animal goat Figure 7 31 A diagram of the Livestock hierarchy generated by selecting View Tree Knowledge Acquisition 66 Chapter Seven Software manual for AKT 7 5 3 BUILDING EDITING OBJECT HIERARCHIES 7 5 3 a Adding objects To build up an object hierarchy or to add to one already extant highlight the relevant hierarchy from the Object Hierarchies list and the Object Hierarchy dialog box will automatically ap
164. ew object should be copied In this case it is crop pest Figure 7 47 Then select whether the object alone should be copied or the object plus its sub objects by selecting the relevant radio button In this case the subobjects of bird chickens ducks and geese cannot be described as crop pests therefore the object bird is moved alone without its subobjects es Move Object treefodd kb ee Move Object treefodd kb KB Name treefodd KB Mame treefodd Hierarchy cite Object Object id 1 Copy To Copy To Hierarchy Plant pest Hierarchy Plant_pest Leaf shedding month Leaf texture Livestock Je Hoops uL Insect pest kali poke object C object suboabjects Figure 7 46 Selecting the new object Figure 7 47 Selecting the object under which hierarchy to which the object is to be copied the object to be copied is to appear Then press Copy The object is then automatically copied to the new object hierarchy Ri It is only possibe to copy objects and objects subobjects from one hierarchy to another not to move them If you want ot move them copy the objects to the new object hierarchy and then detach them from the original object hierarchy as described in 7 5 3 7 6 SOURCES oources are usually entered into the knowledge base when statements are being entered either via the Statements dialog or via the Diagram interface see chapter 8 as a sta
165. f the original consultants is also representative of the knowledge of a wider community will depend on e the heterogeneity of the knowledge held by members of the community on the domain in question and e the impact of the sampling bias when key informants were purposively selected Methodology 47 Chapter Six Knowledge base analysis 6 2 TWO METHODS OF TESTING REPRESENTATIVENESS There are two accepted methods for testing the representativeness of a knowledge base For the first method a questionnaire is drawn up with a list of statements derived from the knowledge base of which half of these are inverted statements giving the inverse of what the informants actually said e g Goats do not eat clover Soil erosion increases soil fertility Feeding orange caterpillars to cattle improves their health The farmers are then asked to agree or disagree with the statement In general if 75 or more farmers agree with a statement then that statement can be regarded as common knowledge The second method is to interview a large random sample of people not included in the original knowledge base creation and to ask them open questions of the type posed to the Original informants taking care not to ask leading questions The information is then analysed and compared with the original response The disadvantage of this second method is that it is time consuming and it makes the analysis of representativeness more difficult
166. h and extension programmes e To explore the distribution of knowledge amongst people within the community and e To augment the knowledge base with details not recorded in the compilation stage Approaches to assessing representativeness are discussed in more detail in Chapter 6 2 1 2 SAMPLE SIZE The number of informants selected for each stage of the knowledge elicitation strategy depends on the nature of the source communities the size and quality demanded of the knowledge base and the time available There are no fixed rules on how many informants should be approached in the scoping stage and it depends entirely upon the methods used for scoping see above 2 1 1 From the definition stage onwards the number of informants grows at every stage So six ten key informants in total might be adequate for the definition stage five for each identified stratum in the compilation stage and 100 for generalisation in a relatively homogeneous local community In general it has proved more productive to speak to fewer people on more occasions than to cover a larger number 2 2 CONSTRAINTS UPON KNOWLEDGE ELICITATION Interview technique is a skill which is best developed through experience This section cannot provide a prescription for how to interview informants but outlines a few important considerations Useful discussions of interview technique can also be found in Werner and Schoepfle 1987a amp b Problems of knowledge elicitation ca
167. h to representation is not constrained by linearity A set of unitary statements may be legitimately explored from any point in any direction As a result diagrams provide a more succinct representation of knowledge than textual approaches A further advantage of diagrammatic representation is that statements entered through the diagramming interface are automatically formalised see Chapter 8 The diagramming interface in AKT uses the grammar to form a precise formal statement without the user needing to understand the syntax of that formal statement Diagrams developed on the basis of this syntax display the following features e every node in the diagram represents an object a process an action or an attribute of an object or process e every node in the diagram is fully labelled e information is attached primarily to links rather than nodes e the meaning of every link is explicitly stated e apair of linked nodes represents information that corresponds to a unitary statement Methodology 30 Chapter Four Knowledge representation 4 4 2 NODES 4 4 2 a Classification of nodes Four types of node are identified Object nodes represent things or more commonly groups of things An object is something that occurs physically e g an oak tree or in an abstract sense e g climate Process nodes represent things that happen e g seed germination or soil erosion Depending on the time scale involved a process might be called an e
168. han same as or different from Finally under some circumstances a link may be represented by the term influence The grammar was designed with a particular emphasis on causal comparison and attribute value statements However management actions i e deliberate actions carried out by the managers of an agroforestry practice are distinguished from ecological processes and can be represented where a statement captures the impact of the management action on the ecology of the practice 4 2 3 FORMAL REPRESENTATION OF SINGLE UNITARY STATEMENTS A detailed description of the application of the formal grammar and justification for its structure is best achieved through example The following guidelines are divided into four parts re evaluation of the single unitary statement identification of fundamental elements identification of statement structural type and creation of the formal statement Looe 4 2 3 a Re evaluation of the unitary statement The first step in the process of formal representation is to reassess the individual unitary statement For each new unitary statement one should ask oneself the following questions i Is the statement clear ii Is it sensible li Is it unambiguous v Is it complete To compare the process of two objects such as growth or germination then the process must be made into an attribute of the object e g rate_of_growth or rate_of_germination Methodology 24 Chapter Four
169. he Boolean Search String and pressed Search the resulting pop up menu the Search Results displays all the statements found by the search Figure 7 63 as Boolean search soil ms Search results soil knowledge base Ble Display Kb terms of type Name of new topic Total number of statements 10 Details r Selected Statement d 0 E formal terms amp sources iter pictis PE za Save search selection List of existing berms in Kb of the specified type Gave 4 New Farmers 193973 Formal Lanquage gccezz 4 E Details Close Close Dewis Numerical Tem anincrease in amount of rainfall causes an increase in rate of soil erosion anincrease in steepness of site causes an increase in rate of soil erosion an increase in rate of soil erosion causes an increase in rate of soil nutrient leaching an increase in amount of mulching of stubble causes a decrease in rate of soil erosion 39 planting of strip causes a decrease in rate of soil erosion 40 planting of cover crop causes a decrease in rate of soil erosion 55 a decrease in depth of soil causes an increase in rate of soil erosion gt an increase in amount of soil erosion causes a decrease in production of crop B Search options Salas f object C subobjects an increase in steepness of field causes an increase in rate of soil erosion i an increase in rate of soil erosion causes an increase in amount of soil erosion Number of terms 9
170. he fertility of black soil is high gt the water holding capacity of black soil is high the production of crop is high if the fertility of soil is high and the water holding capacity of soil is hic the fertility of red soil is high if the rainfall amount is enough and the amount of compost is high the fertility of loose soil is low the fertility of sandy soil is low the amount of red soil erosion is high the amount of loose soil erosion is high the rate of red soil nutrient leaching is low D the rate of sandy soil nutrient leaching is high the amount of sandy soil erosion is high the red_soil depth is deep the loose_soil depth is shallow the black soil depth is shallow the sandy soil depth is shallow the organic content of black soil is high the amount of rainfall is high if the system season is rainy the intensity of rainfall is high if the system season is rainy the steepness of bari is high the steepness of khet is low the frequency of rainfall is low if the system season is summer or the system season is winter SS MONDO ON T2 13 14 15 16 17 18 19 m Diagram Selection Type r Diagram Selection Type All Statements Causes Effects Navigate Print Statements All Statements Causes Effects Navigate Print Statements Figure 7 5 The Statements dialog box in a new knowledge base Figure 7 6 The Statements d
171. high 10 the red soil depth is deep 11 theloose soil depth is shallow 12 the hlack snil denth is shallow Search T opic s SallColaur ar SolT exture 1 k Search Save as Kb Op 7 oO CO PO e Diagram Selection Type All Statements Causes Effects Navigate Print Statements Figure 7 72 Boolean Search String for two topics Figure 7 73 The Search Results dialog box for the combined SoilColour and SoilTexture Boolean Search String in Figure 7 69 7 11 4 CREATING A NEW KNOWLEDGE BASE OUT OF A TOPIC It is also possible to convert a topic or a string of topics into a new knowledge base This option is of use if the original knowledge base has become too large and unwieldy or if so much information exists on a specific topic that it justifies creating a new separate knowledge base It may also be the case when a knowledge base is to be divided up between researchers each with a separate remit to study one particular aspect of the mother knowledge base In order to do this highlight the topics you wish to incorporate into the new knowledge base for this reason it is possible to highlight several topics at once Then press Save as KB This brings you to the Name of new KB dialog box Figure 7 74 where you can save the topics as a knowledge base under a new name and under a new folder directory if necessary oo Hame of new KE Save n E Jed AN Topic s saved a
172. his or her own influence and encourage informants to express knowledge in their own terms d Avoid leading informants into formalising their expressions for the convenience of knowledge structuring e Make the interview atmosphere as relaxed as possible Key points of Chapter Two A knowledge elicitation strategy should contain 4 parts Scoping Definition Compilation Generalisation For knowledge acquisition the informant population may be stratified according to gender age ethnic origin economic status etc in so far as belonging to one or more of these strata will affect the scope of Knowledge of the informants The sample size depends on the size of the source communities their homogeneity and how much time is available In general it is better to interview a smaller number of people more often than a larger number of people only once or twice Interviewing techniques are more an art than a science but can be improved with practice The crucial issue is the attitude of the interviewer towards the informant A student teacher relationship is likely to be far more fruitful than a top down approach on the part of the interviewer Methodology 15 Chapter Three Preparation for knowledge base creation CHAPTER THREE PREPARATION FOR KNOWLEDGE BASE CREATION This following chapters 3 5 detail the procedure for creating a knowledge base within AKT and should therefore be considered and applied in conjunction with
173. hoice of which items to install Installing AKT5 from the Website 1 o Note Create a new folder on your hard drive usually C and call it AKT 5 or something similar Go to www bangor ac uk afforum select AKT followed by Downloads then Program Files After pressing Program Files a Save As dialog box appears Save the file AKT5 Install exe to your new folder To install the program double click on AKT5 Install exe When installing AKT5 from the website the AKT5 Install exe will not give you a choice of the installation type It will only download the compact version to avoid excessive download time The documentation and knowledge bases can then be downloaded later as required Running AKT5 After installing AKT5 and its associated documentation you can then run the application by selecting Start Programs AKT5 Now you are ready to begin Go to chapter 7 Knowledge Bases A number of knowledge bases are supplied with the programme including soil treefodd and atwima mentioned in the manual It is recommended that a separate folder be used for knowledge bases To load a knowledge base and get started turn to Chapter 7 of the User Manual For those of you who have downloaded the manual from the web all the knowledge bases can be downloaded in the same manner go to http www bangor ac uk afforum then select AKT then Downloads then Knowledge base Unzip the files and save them on your com
174. ialog box in an existing knowledge base soil In order to enter a new statement select New The following screen will appear Figure 7 7 requesting information on the Information Source eg Information Source x Please select information source Selected Source Doo OE Type interview amp reference gt Sources none nterview C Reference Close OF tse Details Delete Figure 7 7 Information Sources dialog box The examples used throughout the user guide section of this manual are taken from the two knowledge bases provided with the AKT software soil and treefodd Knowledge Acquisition o4 Chapter Seven Software manual for AKT 7 4 1 ENTERING SOURCE INFORMATION 7 4 1 a New sources It is not possible to enter a new statement via the statement interface without entering the source first because it is most important to identify the source of each piece of knowledge entered into the knowledge base A source may be an informant or it may be a reference from a book or journal or other printed matter e lf you are starting a new knowledge base or using a new source select New e f you are updating a previous knowledge base in which the source has already been quoted highlight the relevant source from the list under Source If entering a new source select the relevant type interview or reference using the radio buttons and either the interview dialog bo
175. icial effect on milk production Might be deleted from a knowledge base in which both relationships were expanded in much greater detail in other parts of the knowledge base Methodology 39 Chapter Five Knowledge base management 5 2 3 AMBIGUITY Unambiguous precise and complete articulation and representation of a unitary statement is required if a useful knowledge base is to be created Most ambiguity encountered in a knowledge base is resolvable being an artefact of articulation and representation However knowledge may be inherently ambiguous so some intrinsic ambiguity will remain in any knowledge base The level of resolvable ambiguity in the knowledge base is influenced by e the nature of the knowledge source e the nature of the knowledge elicitation process e the type of interface used for entering the knowledge i e the statement dialog or the diagram dialog e the experience of the knowledge base developer and the clarity of objectives for creating the knowledge base Resolvable ambiguity is most frequently exposed during the processes of formal representation and the creation of the glossaries and hierarchies Both processes demand a precise use of terms Where ambiguity is the result of inadequate unitary statements it may be resolved through reference to interview material However where ambiguity is a result of incomplete or muddled articulation by the knowledge source further knowledge elicitation is d
176. idually appear reasonably intuitive their combination into a diagram suggests that important information is missing Burning will certainly raise soil temperatures but it is likely that the warming of the soil referred to in the text is not actually a direct consequence of burning but of the removal of vegetation as a result of burning and the consequent increase in insolation Modification of the above diagram may better capture this interpreted meaning see Figure 14 2 below Tutorials 159 Chapter Fourteen Tutorial in creating a simple knowledge base soil insolation level site an increase in lewel of zoil clearing Insolation causes an increase in temperature ot soll clearing of site causes an Increase in temperature of soil zoil temperature an increase in temperature of soll causes an increase in rate of organic matter decomposition fegetation removal vegetation removal causes an Increase in lewel ot soll insolation burning of site causes vegetation removal site burning burning of site causes a decrease In number ot pests pests number f decomposition disease rate levels Figure 14 2 Figure 14 1 modified to better capture the interpreted meaning buming of site causes a decrease In levels ot disease organic matter 14 3 2 ENTERING KNOWLEDGE THROUGH THE STATEMENT CARD Although statements entered through the diagram interface are formalised autom
177. ientists scientists crop p scientists_fodder 2 Figure 7 79 Message confirming that a new tree fodder i tree_crop topic hierarchy has been saved Figure 7 78 New Topic Hierarchy dialog box Unlike Object Hierarchies where it is possible to create a new name for the hierarchy the name of the new Topic Hierarchy must come from one of the topics already created Highlight the chosen topic in the Topics box If you want to make sure how the topic was originally defined i e the Boolean Search String used select Details After checking the details press Save A message will appear confirming that a new topic hierarchy has been saved figure 7 79 and the topic name will now appear in the Topic Hierarchies list of the Topic Hierarchies dialog box Figure 7 80 Knowledge Acquisition 88 Chapter Seven Software manual for AKT ms Topic Hierarchies treefodd kb This knowledge base contains information classified under different categories called topics These topics may be organised under different topic hierarchies To see the statements defined by a particular topic hierarchy first select the topic hierarchy then click on the statements button Selected Topic Hierarchy Topic Hierarchies x Mew Delete Topics in selected hierarchy Close Save Topic Hierarchy as new KB View Topic Hierarchy Statements Figure 7 80 The new topic hierarchy appearing in the Topic Hierarchie
178. ies identifying terminologies and creating a framework oources are purposely non randomly selected from the source community These key informants are selected on the basis of interest articulateness depth of knowledge and willingness to participate Key informants known to be in some way significantly unrepresentative of the community as a whole for example school teachers in local farming communities have tended to be avoided although they are often helpful in identifying other key informants Because the definition of the domain has a significant impact on the shape and content of the final knowledge base an adequate spread of key informants is desirable to maximise the chances of developing a representative framework within the time available for this stage of knowledge acquisition 2 1 1 c Compilation The compilation stage of the knowledge elicitation strategy is used to record detailed knowledge within the framework developed in the definition stage and to indicate the variability of knowledge over the community as a whole The focus at this stage is on talking to a few knowledgeable people in depth rather than attempting to obtain statistically representative samples As repeated interview of the same person is of paramount importance in obtaining deeper explanatory knowledge and resolving inconsistencies willingness to participate must be an important criterion for selection of key informants For local communities a small s
179. ight be distinguished from the process of browsing where livestock actively seek out and select fodder on trees This process of selective browsing may mean that fodder effects relating to stall fed livestock do not occur for free range livestock This example illustrates something of the range of activities that can be involved in iterative evaluation and improvement of the knowledge base The following sections anatomise some of the key processes occurring in iterative evaluation Methodology 38 Chapter Five Knowledge base management 9 2 EVALUATING INDIVIDUAL UNITARY STATEMENTS Individual unitary statements may be evaluated in terms of validity of representation relevance utility and ambiguity 5 2 1 VALIDITY OF REPRESENTATION oome evaluation of the validity of representation to check whether the knowledge statement has been correctly encoded is built into the process of creating formal statements directly or through diagramming This is due to the restricted structure of the formal grammar the use of a parser and the stylised English generation in formal representation by AKT It cannot be overemphasised how important it is that when formulating unitary statements prior to creating a formal statement these unitary statements should be rigorously checked to ensure that they conform to the definition of a genuine unitary statement For example the statement Nutrient uptake by fodder trees planted on crop land causes a
180. igure 7 66c Causal flow out of statement no 32 Knowledge Acquisition 82 Chapter Seven Software manual for AKT i To summarize Diagram Selection Type All Statements gives you a diagram of all the statements extracted by the Boolean Search which can be presented in diagrammatic form i e causal and link statements Causes gives you a diagram of all the causes of one statement selected from the statements extracted by the Boolean Search Effects gives you a diagram of all the effects of one statement selected from the statements extracted by the Boolean Search Navigate gives you a diagram of all the immediate causes and effects of one statement selected from the statements extracted by the Boolean Search 7 10 2 USING THE BOOLEAN SEARCH ON OBJECT HIERARCHIES For the objects amongst the formal terms selected in the Boolean Search String a choice of search modes is available in the Search options box object subobject and superobject see above Figure 7 62 By highlighting one or more of these options there are 7 possible combinations for the Boolean search For example object alone recognises only those statements in which the object selected is actually used object plus subobject extracts unitary statements in which either the specified object or the children and descendants of that object in the object hierarchy are used and object plus subobject plus superobject ext
181. imply an alphabetical list of terms Items are added to glossaries automatically during the process of formal representation The details of each term can be accessed by selecting Details The Formal Term Details dialog box Figure 7 53 gives the formal term type its definition and any synonyms there may be If you select Show use in statements a dialog box Search Results appears giving all the statements in which the formal term appears Figure 7 54 For objects itis also possible to select Show use in hierarchies If the object appears in any hierarchies the relevant hierarchy names will appear Figure 7 55 In the example below the formal term cattle appears in three formal statements and in the object hierarchy Livestock ee Formal Term Details treefodd_kb Definitions we Formal Terms treefodd kb KB Mame treefadd EN allaichi_ bari Synonym allelopathy altitude Show use in statements Show use in hierarchies always amalla Figure 7 53 Details of the Formal Term amliso cattle in the treefodd kb knowledge base amount animal Animal feed Figure 7 52 Selecting the type of formal term in the Formal Terms dialog box Knowledge Acquisition 14 Chapter Seven Software manual for AKT ee Search Results treefodd_kb E Hierarchies KB Name treefadd Number af Statements 3 Selected Statement Details AN Livestock Matural Language bene Formal Language 4
182. in the list but it is It is important to drag the mouse in the same direction as the causal flow i e in the same direction as it was dragged to create the link otherwise the link possible to have more than one statement associated with the same pair of nodes will not be deleted A dialog box will then appear in which the sentence to be deleted must be selected Once the sentence is highlighted press Delete Once Delete has been selected the following message appears Figure 8 28 giving the natural language version of the statement and checking whether it is to be deleted Knowledge Acquisition 116 Chapter Eight The diagram interface ws WIN PROLOG x us WIN PROLOG E E 2 E 2 Ebo oce ELE causes an decrease in the rate of the process of f 2 p Are you sure vou want to delete this statement Figure 8 28 Message requesting you to confirm that Figure 8 29 Message asking the statement should be deleted whether the node information should be deleted from the knowledge base as well If No is selected the whole process is abandoned If Yes is selected a message as in Figure 8 29 appears checking whether the nodes are to be deleted as well If Yes is selected both the nodes will disappear as well as the link if No is selected the nodes will remain unattached as in Figure 8 30 It would then be possible to create a different link either a causes2way or a simple link lin
183. ing also accelerate the decomposition of organic matter in the top layers of the soil Under the Diagram menu select Show Kb Diagrams This will give you a blank diagram window with all the function buttons displayed on either side Entering a statement through the diagram interface demands some thought about the structure of that statement For full details of the diagramming syntax see Chapter 4 section 4 4 The section on formal representation Chapter 4 section 4 2 will also clarify the structures of statements supported The following five statements might be abstracted from this paragraph Tutorials 157 Chapter Fourteen Tutorial in creating a simple knowledge base Table 14 2 Statements abstracted from the first paragraph Burning causes a decrease in pest numbers Burning causes a decrease in disease levels Clearing causes an increase in soil temperature Burning causes an increase in soil temperature An increase in soil temperature causes an increase in the rate of decomposition of organic matter Each of these statements can be represented in the diagramming interface as a pair of nodes and a link between them In the case of the first statement the two nodes are burning an action and number of pests an attribute number of an object pests To represent this statement 1 2 o Oe 13 14 Select the Action button from the Add node box on the left hand side of the diagram s
184. ing the primitives as shown above normally only system or user tools will be run like this primitives tend to be used within the bodies of other tools 9 2 2 CONTROL STRUCTURES There are six control structures available in the AKT task language for use in the creation of reasoning tools To view the available control structures select the control structures from the drop down menu under Tools in the main Tools menu Control structures find all salutionsi Term Goal Solutions tareach in da Element List Call if theniP an if then amp lse F GLP repeat untiliCall Test Primitives avstem Tools wr Cr CF WM Iser Tools test each in list fariElement List Goal Passes Fails Figure 9 5 Drop down menu for control structures Control structures are pieces of code which are used to link one primitive to another to construct a tool they are if you like the glue that binds the primitives together Name of control structure Function of control structure Find all solutions Term Goal Solutions This structure allows you to find all solutions to a specified goal The goal can be a primitive a system or a user tool or any combination of them Foreach in do Element List Call The operation detailed in Call or Goal is executed in turn for every item in the specified list If then P Q In this structure P is a primitive or tool or any combination of primitives and tools which returns a r
185. ion in the Topic Hierarchies dialog box and select as new KB from the Save Topic Hierarchy box The procedure is then identical to that of saving a topic as a new knowledge base see above 7 11 4 Knowledge Acquisition 90 Chapter Seven Software manual for AKT 7 13 PRINTING AND SAVING SEARCH RESULTS In many cases it may be desirable to print out or to save search results made via the Formal Terms or Boolean Search dialog boxes In order to do so press Print Statements at the bottom of the Search Results dialog box Figure 7 85 A message appears Figure 7 86 asking whether you wish to save the output to a text file ms Search Results treefodd kb IL PAATE xc 2 Would you like to SAWE the output to a text file KB Mame treefodd Number of Statements 8 Selected Statement Matural Language ean Formal Language Figure 7 86 Message which appears when you Select Print Statements AO a decrease in frequency of lopping of foddertree causes an increase in number of new shoot B3 an increase in temperature of air causes an increase in number of new shoot 90 an increase in number of nades left of branch causes an increase in number af new shoot 171 a decrease in number of new shoot causes a decrease in Foliage biomass of tree 172 an increase in number of new shoot causes an increase in density of crown 10153 branch drying causes a decrease in number of new shoot 1132 the lopping
186. ion 7 6 ms Statement Sources soil kb ee Statement Sources soil_kb KB Mame soil Statement Ma 39 KB Mame sail Statement Ma 38 Selected Source BERERE Selected Source Gurung 199 7a Type interview amp reference Type interview amp reference Statement Sources Details Statement Sources Details Farmers 199 a Farmers 199 a Close Gurung 19974 Edit Sources Append Farmers 1997a Detach Farmers 1997a Detach Gurung 1997a Gurung TS aa Figure 7 19 Statement sources dialog box Figure 7 20 A new source appended to Statement Sources list In order to append a source to the statement in the Edit Statement dialog box select Sources The Statement Sources dialog box appears Figure 7 19 Highlight the source you wish to append to the statement from the Sources list and then select Append A message will appear confirming that the source has been appended to the statement Figure 7 21 and the newly appended source will appear in the upper list under Statement Sources see above Figure 7 20 If you wish to detach a source from a statement highlight the source to be detached from the statement in the Statement Sources list and select Detach The source will be removed from the Statement Sources list although it will remain in the Sources list A message will appear confirming that the source has been detached from the statement Figure 7 22 we Append Source es Detach S
187. ion into or extracting information from a tool e Tool Definition a Tool name and parameters b tool body Using Knowledge 135 Chapter Ten Creating your own tools a The toolname must start with a lower case letter e g find trees or if it is required to start with a capital letter then the whole toolname must be enclosed in single quotes e g Find trees The arguments or parameters contained in parenthesis after the toolname generally begin with a capital letter indicating a variable but they can be a fixed value if required For example Kb and Date are variables but attributes and John Smith are fixed values The toolname should express succinctly the function carried out by the tool b The tool body contains all the functions control structures and appropriate punctuation that allows the tool to perform the required process If the tool body does not have the correct form or syntax then AKT will report a Syntax Error whenever an attempt is made to save the tool or the syntax check button selected 10 4 1 INCORPORATING EXISTING TOOLS PRIMITIVES WITHIN A NEW TOOL DEFINITION There are various ways of adding a primitive systems tool control structure or previously defined user tool to the definition of the new tool two possible ways using cut and paste functions are described below Method 1 Select the Browse Tools box from the New Tools dialog box see above Figure 10 11 This will display a list of all
188. ir F L Joshi L amp Ambrose B 1997 Prospects for the use of corporate knowledge bases in the generation management and communication of knowledge at a frontline agricultural research centre Agricultural Systems 54 291 312 Walker D H Sinclair F L amp Muetzelfeldt R I 1991 Formal representation and use of indigenous knowledge about agroforestry pilot phase report June 1991 School of Agricultural and Forest Sciences University of Wales Bangor Warren D M ed 1991 Indigenous agricultural knowledge systems and development Agriculture and human values VIII 1 amp 2 Warren D M Slikkerveer L J Titilola S O eds 1989 Indigenous knowledge systems implications for agriculture and international development Studies in Technology and Social Change Technology and Social Change Program No 11 lowa State University Warren D M Slikkerveer L J amp Brokensha D eds 1995 The cultural dimension of development Intermediate Technology Publications London Werner O amp Schoepfle G M 1987a Systematic Fieldwork Volume 1 Foundations of Ethnography and Interviewing Sage Publications Werner O amp Schoepfle G M 1987b Systematic Fieldwork Volume 2 Ethnographic Analysis and Data Management Sage Publications Whyte A 1977 Guidelines for field studies in environmental perception Man and the Biosphere technical notes 5 Paris UNESCO 171
189. is selected then tool will succeed with Response No calculate Function Result Miscellaneous lise ane or mare arithmetic functions to calculate a Result Figure 10 12 List of Tools available in Help on the main menu The list is alphabetical and gives the tool name and the category to which it belongs and the description of what it does Using the scroll bar enables you to select the tool you require Using Knowledge 136 Chapter Ten Creating your own tools Highlight the tool name and parameters but not the category nor the definition and press Ctrl c Return to the New Tool dialog box and setting the cursor in the tool body box press Ctrl v to paste it into the tool 10 4 2 TESTING THE SYNTAX OF A NEW TOOL In order to check whether or not the syntax of the tool is correct select Syntax Check If there is an error in the syntax anywhere within the tool one of the following messages will appear Figures 10 13 and 10 14 mw ERROR es WARNING TOOL UNDEFINED AN SYNTAX ERROR in the body of the tool AN Tool definition contains a call to an undefined tonl Figure 10 13 Error message which appears Figure 10 14 Message received if a non if the format of the control structure is wrong existent tool has been used or the punctuation incorrect A syntax error occurs when the format of the tool head or body does not correspond to the Prolog syntax which is used by the code underlying the AKT application A cal
190. itional information associated with a unitary statement provides important contextual information about the application of that unitary statement However exhaustive recording of the context of application is impractical some level of understanding from common knowledge for the evaluation of the knowledge base as a whole must be assumed Judgement of the completeness of conditional information is subjective and dependent upon context It is important that where a statement is considered to be unconditional this is explicitly recorded 5 2 3 c Precise use of terms Another source of ambiguity is the imprecise use of terminology The definition of terms and the consistent use of terms are discussed later see 5 3 4 Here the concern is with the imprecise use of terms within a statement A widespread example in existing knowledge bases is the use of the term shade A unitary statement often refers to one aspect of shade for example a change in light levels light quality or temperature rather than a composite of all shade effects 5 2 3 d Intrinsic ambiguity In a fundamental sense virtually all knowledge is ambiguous at some level In the current context however intrinsic ambiguity is of interest where it has an impact on the practical utility of knowledge Ambiguity is intrinsic where the source of an ambiguous statement cannot resolve the ambiguity in that statement This is generally because the ambiguity is not clear to the informan
191. itives d system Tools d General User Tools d Hypothesis Knowledge Analysis Knowledge Evaluation Knowledge Exploration T F F F F F Quer Figure 9 6 The drop down menu for System Tools The following is an explanation of the different categories of systems tool available aae other categories Analyses the effect s of a statement or formal term s on the knowledge base Knowledge Evaluation Evaluates the contents of the knowledge bases and checks for example inconsistencies or redundant information within the knowledge bases Explores the knowledge base for the implications of processes and management actions Query Allows the user to determine if anything in the knowledge base matches any type of formal statement specified by the user Using Knowledge 125 Chapter Nine Reasoning with AKT tools 9 3 1 SOME EXAMPLES OF SYSTEMS TOOLS a System Tool Category Knowledge Evaluation System Tool kb_report 1 The System Tool kb report 1 is in the category Knowledge Evaluation Figure 9 7 we ools manual Type system tools M sec Tool output kb_report 1 Selected Kb sail Output m Knowledge Evaluation tools 34 r Tool Options 4 kb report 1 Bun Details Wer Delete t Close Results of running the tool Call kb repart 1 2 Jan2000 at 1253 hrs kb soll Total number of statements 113 of which 12 are conditional Number of attribute statements 24 of which 8 are
192. ize However even where large boards or paper are used diagrams rapidly become Methodology 33 Chapter Four Knowledge representation unsustainably complex It is the clear representation of links rather than nodes that presents difficulties Typically a node will be linked to between two and five other nodes With an increasing number of nodes it becomes increasingly difficult to place nodes near to all the other nodes to which they are linked links have to travel further across the diagram crossing increasing numbers of nodes and links until the diagram becomes impenetrable The placement of nodes the technique used for representing the meaning of a link and the arrow type used to link nodes all have an impact on the number of nodes and links that can be successfully represented nevertheless fundamental limitations will still be reached In order to overcome some of these problems sub diagrams can be built up from the main diagram It is possible to make a sub diagram of the pathway between any two nodes on the diagram It is also possible to build up a diagram by selecting any number of nodes greater than one for which the system will then produce a sub diagram showing all the connections 4 5 CREATING KNOWLEDGE BASES THROUGH THE COMBINATION OF EXISTING KNOWLEDGE BASES In parts 4 1 4 4 the creation of knowledge bases from scratch has been described However it is also possible and may frequently be desirable to create a knowl
193. k or to add new nodes and rearrange the links between them ewapotranspiration rate Figure 8 30 Unattached nodes Ri Any changes made via the diagram interface will result in the same changes being made to the statement interface and vice versa 8 10 ALTERNATIVE ROUTE TO EDITING DIAGRAMS An alternative way of altering a diagram is to select Statements from the main KB menu From the Statements dialog box it is possible to edit the statement in question See Chapter 7 4 3 Once the statement has been edited and saved closing the Statements dialog box will return you to the Diagram screen with the diagram updated where appropriate Knowledge Acquisition 117 Chapter Eight The diagram interface PRINTING DIAGRAMS If you wish to print a diagram directly from the screen press the Print Window button on the right hand side of the screen If you wish to export the diagram to another package before printing do Copy to Clipboard as explained above in 8 6 3 Knowledge Acquisition 118 Chapter Nine Reasoning with AKT tools CHAPTER NINE REASONING WITH AKT TOOLS 9 1 INTRODUCTION An important part of the AKT application is the task language This consists of a number of primitive or system tools together with a choice of control structures in which the tools can be combined to perform tasks defined by the user The resulting definition can then be saved as a user defined tool for future use Th
194. l be empty me User defined tools in file new mcr x New Tool aeua Tool user_defined Current Tool new Categor Description Bano m Tools Tool Options4 Ah Run Test Details Trace Paramete mut T BERLE ees Output o f Cose Close Tool Definition Tool Name Parameters syntax Check No of Tools 0 B Browse Tools 4 4 Tool Body Note Must finish with a full stop then a new line __Print Tool Figure 10 10 User defined tools dialog box Figure 10 11 Dialog box for the creation of a new tool In order to create a user defined tool select New A New Tool dialog box appears Figure 10 11 The information that must be specified about a tool includes e Description of the tool s function The Description written in plain text should describe the tool s function and give instructions for its use It is worth remembering that if the knowledge base is to be used by others then the description should be as informative as possible e Input and output parameters The input and output parameters arguments required by the tool Parameters are the means of passing information into or out of the tool Each tool can have any number combinations of input and output parameters A tool does not necessarily need input parameters nor output parameters it depends on its function You only need any parameters when you are passing informat
195. l to an undefined tool on the other hand means that the name of a tool used in the function does not exist It may have been incorrectly spelt or the number of parameters may be wrong As the message does not tell you specifically where the error lies within the tool it is useful to carry out a syntax check after each new line is added In order to do this you can temporarily put a full stop at the end of the new line and follow it with a carriage return then press Syntax Check If a message Tool syntax is ok appears then you can continue building the tool first removing the full stop and replacing it with a comma before starting a new line If a message appears as in Figure 10 13 or 10 14 above then you should not proceed to a new line until the current line of instructions has been corrected 10 4 3 AN EXAMPLE OF CREATING A TOOL The best method of explaining how to create a tool is by demonstration In this example we are creating a tool which will list all the statements related to a specified term or terms and then saving these statements in the form of a new knowledge base Select New from the user defined tools Tool dialog box as above Figure 10 10 and the New Tool dialog box appears as above Figure 10 11 First give a description of what the tool does in the Description box In this case a sentence such as This tool collects all statements relating to a user specified term terms and then saves the
196. ledge but to collect the knowledge of a community rather than an individual 4 2 FORMAL REPRESENTATION 4 2 1 INTRODUCTION Because of the ambiguity and complexity inherent in natural language accurate interpretation of unitary statements in unrestricted natural language may often be difficult Natural language is extremely robust in its use and interpretation it can contain a great deal of ambiguity and imprecision yet still serve a useful function in communication Meaning in natural language is often context specific and therefore flexible However it cannot be assumed that the implicit contextual meaning of a unitary statement will still be understood by users once it has been included in a knowledge base Furthermore automated reasoning techniques cannot cope with flexibility of meaning according to context As a result the second stage in the creation of a knowledge base is to create a version of the unitary statement that conforms to a formal syntax This process is known as formal representation The process of formal representation results in statements that have a fixed syntax and can therefore be combined using inference mechanisms in automated reasoning see Chapter 9 The process also provides a means of evaluating the knowledge already elicited rationalising terminology and identifying ambiguity inconsistency and so on see Chapter 9 Formal statements comprise a set of terms linked by and ordered in relation to other sp
197. ledge base and retain the original version by giving the most recent version a new name or to save the knowledge base in another folder or directory S WARNING If you decide to change or edit the name of any knowledge base it must only be done from within AKT via the Save KB As option If it is done any other way then AKT will not be able to load the knowledge base correctly Knowledge Acquisition 92 Chapter Seven Software manual for AKT 7 15 MOVING FROM ONE KNOWLEDGE BASE TO ANOTHER It is possible to load more than one knowledge base onto the program at a time The advantage of this is that it enables you to switch quickly from one knowledge base to another without exiting the program something which is of particular value when running the tools see Chapter 9 In order to load the knowledge bases onto the program simply select Open KB from the main KB menu and then choose the knowledge base you want You load the knowledge bases one at a time selecting Open KB each time The most recent knowledge base to be loaded will be the one that appears on the screen To move from one knowledge base to the other select Select KB from the main KB menu The following dialog box appears Figure 7 90 oe Select a knowledge base Current treefodd Selected Files Cancel Figure 7 90 Moving from one knowledge base to another In this example the current knowledge base is treefodd The other two knowledge bas
198. lighting the statement and then pressing Delete However BE WARNED If you delete a statement from this dialog box you not only remove the statement from the diagram interface you also remove it from the knowledge base Find If you want tofind the position of a statement within a diagram highlight the statement and press Find The diagram will then return to the screen with the two nodes of the selected statement highlighted Print If you want to print out a list of statements press Print You can then either save the output to a text file or print it directly from the screen Close If you press Close you will return to the diagram screen Knowledge Acquisition 108 Chapter Eight The diagram interface 8 4 2 STATEMENTS FOR A SUB DIAGRAM When a sub diagram has been created selecting Statements will give you all the statements used in creating that sub diagram Figure 8 19 is a list of the statements making up the sub diagram in Figure 8 16d Ri If you use the Hide function for several nodes and links within the sub diagram the nodes and links which you have hidden will not appear in the statement list of the sub diagram 11 of the 73 knowledge base statements are represented in this diagram i el Ea 30 an increase in usage of fertilizer causes an increase in fertility of e a 37 a decrease in fertility of soil causes a decrease in production of crop 45 an increase in availability of forest fadder ca
199. livestock if there are orange caterpillars on the leaves Whilst this is now explicit representation of a piece of knowledge the word can along with a lack of any information about the circumstances under which the statement is held to be correct makes it of limited utility This suggests a need for further knowledge elicitation possibly revealing that this always occurs i e Feeding leaves to livestock causes sickness to those livestock if there are orange caterpillars on the leaves This statement can now be meaningfully formalised Leaves livestock and orange caterpillars are objects Feeding is an action Sickness might be viewed as a process or to be a change decrease in the value of an attribute health This statement might be formalised in many different ways all capturing essentially the same meaning but with different emphases for example action feeding leaves livestock causes att value livestock health decrease if att value orange caterpillars location on leaves Or action feeding leaves livestock causes att_value livestock health decrease if att_value caterpillars location on_leaves and att_value caterpillars colour orange In other contexts a more precise definition of the results of consuming orange caterpillars may be necessary sickness may be considered to be a particular type of decline in health that has particular consequences the difference between the sickness caused by orange
200. lopment programmes e The process of creating a knowledge base can have a significant impact on the knowledge base developer s understanding and perception of domain under investigation e Formalisation of knowledge enables the comparison of knowledge from different sources e g farmers and scientists Methodology 10 Chapter Two Knowledge Elicitation CHAPTER TWO KNOWLEDGE ELICITATION In contrast to the later stages of knowledge base creation which will be described knowledge elicitation does not need to conform to a specific set of guidelines Indeed approaches to knowledge elicitation that are appropriate in one context may be inappropriate in another The contents of this section should therefore be regarded as suggestions and examples of approaches to be adopted as appropriate to circumstances 2 1 DESIGNING A KNOWLEDGE ELICITATION STRATEGY Generally it will not be possible to elicit knowledge from all appropriate sources when creating a Knowledge base particularly when eliciting information from a local community Therefore a sampling strategy must be designed This should enable the efficient development of a knowledge base that is representative of the knowledge of a defined community or set of communities The sampling strategy should also incorporate a return to the source community to test how well the new knowledge base represents the knowledge of the community as a whole 2 1 1 AFRAMEWORK FOR DESIGNING A KNOWLE
201. losed canopy forest greater than open canopy forest 4 2 4 d User defined Link statements This link is specified as user defined link in order to distinguish it from certain reserved terms that act as links between two parts of a statement For example the reserved terms causes way causes2way greater than less than same as link the two halves of a formal statement together User defined links on the other hand are terms selected by the user User defined link statements take the basic form link link type Object1 Object2 Ecological relationships such as cows eat grass and bees pollinate clover are good examples of user defined link statements and would be expressed in formal language thus link eat cows grass link pollinate bees clover User defined link statements are also used when the knowledge cannot be expressed using any of the other three types of statement e g Tithonia diversifolia is found on unfertile ground or oak is used for timber These would be formally represented as link is found on Tithonia diversiflora unfertile ground link is used for oak timber The grammar includes one type of link statement in which the link type is influences In this instance the link may be between any combination of objects and processes Influence relationships are very closely related to causal relationships However in an influence relationship there is no information on what attribute of the object or process
202. m These above ingredients provide the basis for formal representation Using different combinations of these there are four types of statement that can be formed e Attribute Value statements e Causal statements e Comparison statements Methodology 23 Chapter Four Knowledge representation e User defined Link statements See 4 2 4 below 4 2 2 a Reserved terms e The term comparison enables the comparison of the value of an attribute for two objects e The term causes allows a causal relationship between an attribute value statement object process or action and another attribute value statement process or action to be captured e The term if allows conditionality to be captured whereas the terms and and or allow multiple conditions to be specified for a unitary statement e he term part allows a particular part of a specified object for example the roots of wheat to be represented e The term not can be used to capture negation e g pigs do not eat grass The term link allows relationships between objects or processes other than causal or comparative links to be captured e g cows eat grass Some elements of formal statements may be represented by atoms that have special meanings and are used in particular contexts For example a value may be represented by the special terms increase decrease change no change and range Comparison types can be expressed by one of the following terms greater than less t
203. m as a new knowledge base will express its function adequately The toolname saveStatements ToKb acts as a sufficient aide memoire for its function Note that the first letter in the tool name is in lower case In this instance there are two externally supplied parameters needed to make the tool run the knowledge base you are interrogating the term or terms you are looking for Thus the full name of the tool will be saveStatements T oKb Kb Term Then move the cursor down to the tool body The tool we wish to create should do the following things Using Knowledge 137 Chapter Ten Creating your own tools search for all the statements about a given term or terms in a specified knowledge base save the formal statements as a separate knowledge base convert the formal statements into natural language display the statements in natural language Q O O f C NAN ay BEFORE YOU START SYNTAX CHECK As you build a new tool you should carry out a syntax check after each new line so that any source of error can easily be traced See above 10 4 2 For a we need the primitive statements_search Kb Term Hierarchy SearchOption StatementsIn ListFormalStatements We access this by pressing Browse Tools in the New Tool dialog box as above Figure 10 11 and selecting Primitives then Statement We then highlight the primitive required and press Details From the Details dialog box we highlight
204. m per annum AND vegetation cover is thin but it does not give any indication of the confidence the informant or others have in this particular piece of knowledge Although attempts have been made to capture the degree of confidence in a statement it was found that informants were uncomfortable in providing statements of confidence in part because it appeared to question their veracity 4 1 3 b Source One important piece of contextual information for the interpretation and use of knowledge is the source of that knowledge Where a user of knowledge is familiar with or aware of the informants references this will inform his her use of that knowledge For this reason knowledge is tagged according to source This also facilitates the assessment of the internal consistency of knowledge from a particular source and the distribution of knowledge between sources There is an ethical need to enter the source of Knowledge otherwise one may lay oneself open to accusations of extractivism By recording the source of knowledge it is also possible Methodology 20 Chapter Four Knowledge representation to identify whose knowledge is being used at any time so that if there is any value attached to that knowledge it can be attributed to the original source However in general the methodology is designed to record how a community understands the resources on which its livelihood is based and the purpose is not to seek out specialist valuable know
205. main KB menu 7 5 1 CREATING OBJECT HIERARCHIES A new object hierarchy is created by selecting New Figure 7 27 In the new dialog box that appears New Object Hierarchy Figure 7 28 a new hierarchy name has to be given The New Hierarchy Name can be either one of the objects which occurs in the unitary statements or it can be a completely new name not directly related to any of the unitary statements but Knowledge Acquisition 64 Chapter Seven Software manual for AKT which provides a means of identifying the relationship between the other objects appearing in the hierarchy Enter the name and press Save Eg Object Hierarchies treefodd ES pg New Object Hierarchy treefodd E Eb Mame teefodd Object Eb name teetodd New hierarchy Object Hierarchies ew Fodder animal ty Delete Figure 7 28 Dialog box for New Object Fodder_overripen Fadder quality Hierarchy Fadder ripening I Interim Leaf flushing mar Leaf shedding m Leaf texture Livestock Close Figure 7 27 Dialog box for object hierarchies Once a hierarchy name has been entered and saved the dialog box will revert to the Object Hierarchies dialog box with the new hierarchy name included in Object Hierarchy list 7 5 2 VIEWING OBJECT HIERARCHIES To view an object hierarchy highlight the relevant hierarchy from the Object Hierarchies list in the Object Hierarchies dialog box and the object hierarchy de
206. main menu Sources Go to the main menu and select KB Sources These are a list of all the sources interviewed for the knowledge base No statement can be entered into the knowledge base without the author of the statement being entered into the knowledge base first Let us look at one of them Highlight the name Asmoah et al and press Details A dialog box appears giving you the name of the interviewer interviewee sex of interviewee and date of interview If you press Memo it will give you any further details that the knowledge base creator felt to be important Press Close on all three dialog boxes Topics Return to the main menu and select KB Topics This gives you a list of all the topics in the knowledge base Highlight Management actions and press Details Edit In the dialog box that appears you will see in the Boolean Search String how the topic was created it is a Boolean search string of al management actions burning clearing cutting harvesting planting uprooting use work If you press Statements at the bottom of the dialog box a list of all the statements on management actions appear There are 107 statements in all on that topic You can try the same thing out with the topic Weed control Frost W 2000 Farmers knowledge of soil fertility and weed management in Atwima district Ghana WinAKT Knowledge base University of Wales Bangor Tutori
207. me sick if they eat Khasru is an example of a because the user needs to know that Khasru is eaten By contrast and as an example of b it might be assumed that any user of the system can interpret the statement Utis is a tall tree as being about the height of the tree while formal representation demands that this is explicitly stated i e the height of the Utis is tall Attributes are often implicit For example in the statement Loam is very fertile loam a type of soil is an object very fertile is a value but it is not immediately clear of what this value is a measure i e the attribute to which it refers However the attribute must be identified in formal representation Soil fertility might be suitable in this case By contrast objects processes and values are implicit only occasionally usually only where the unitary statement is inadequate as with the implicit process in the first example above or where representing statements that stretch the use of the grammar For example the statement Rainfall is maximum in January does not contain an explicitly stated object Rainfall is taken to be a process In other circumstances it might be viewed as an object but maximum in January implies that the attribute is a rate rather than a volume Rates can only be associated with processes and actions So maximum is a value for the attribute rate of the process rainfall January is a
208. ment of the definition of a term all existing uses of that term in unitary statements must be checked to ensure a valid use of terminology Key points of Chapter 5 Formalised unitary statements must be unambiguous and a valid representation of the original statement terative evaluation of sets of statements for avoiding repetition and contradiction and for ensuring completeness and consistent use of terms leads to a concise knowledge base which optimises its utility Hierarchical arrangement of objects in the knowledge base is a powerful feature which enables valid representation of object classification and this helps compact a knowledge base significantly Methodology 46 Chapter Six Knowledge base analysis CHAPTER SIX KNOWLEDGE BASE ANALYSIS 6 1 EVALUATION OF THE REPRESENTATIVENESS OF A KNOWLEDGE BASE The four stage knowledge elicitation strategy outlined in Chapter 2 provides a means for eliciting Knowledge which relies initially on particularly Knowledgeable experienced and co operative informants or key texts Users of the resulting knowledge bases will assume that the contents are representative of the knowledge of a defined source community or communities Therefore any use of the knowledge base must be informed by an evaluation of the representativeness of the knowledge base This chapter illustrates some of the approaches taken for testing representativeness 6 1 1 DEFINITIONS OF REPRESENTATIVENESS Defini
209. ments in the knowledge base that match the query In the example below Figure 9 9 and 9 10 all the soil knowledge base statements have been examined and any attribute phrases matching the AKT expression att value O A V have been found Using Knowledge 126 Chapter Nine Reasoning with AKT tools we Query soil ee Query output soil os Selected Kb Kb Name soil 4 Z Output Solution Options tt_valuefblack_soil fertility high Add Term att _ Soll y nig First Nest a mm att value black soil water holding capacity high ose Figure 9 9 Using E y soil att value process sandy soilerosion amount high statement q uer y 0 to fin d a II att value red soil depth deep E att_value loose_soil depth shallow a ttr 1 b U te Va ue ph rases of a att value black soil depth shallow att value sandy soil depth shallow C ert ain fi orm at att_value black_soilorganic_content high att_value bari steepness high att value khet steepness low no more solutions Figure 9 10 The output window for the statement query att value O A V c System tool category General merge External Statements This tool enables you to merge statements from an external knowledge base into the current knowledge base If you select this tool and press Run a directory appears with the legend Kb containing the statements to be merged from which you select the knowledge
210. n after the translated statement The control structure foreach in do insures that the instructions a b and c are carried out for each statement in the selected topic containing the specified term until all such statements have appeared on the screen Finally note that the last line contains the closing bracket for the control structure and a full stop You must always add a carriage return 1 after the full stop to complete the tool See the Description box for the primitive statements convert Mode Kb Original Converted to see the full list of mode options Using Knowledge 134 Chapter Ten Creating your own tools The Trace button To observe the various functions of the different steps select the tool search_Topic_Statements once more and in the Tool Details dialog box press the Trace button This will take you through the tool step by step This function is particularly useful if a tool does not function properly You can see at which step the error lies 10 4 CREATING YOUR OWN TOOL In order to create a new tool in AKT it is necessary for a user file to be opened to contain the tools Open the main Tools menu and select either New Tool File or Open Tool File see above section 10 2 Once a new tool file has been created or an existing tool file opened a dialog box will appear showing a list of User defined tools Figure 10 10 If no tools have been previously created by the user this dialog box wil
211. n arise because people often fail to recognise that they have knowledge let alone how they use it Hart 1986 and thus informants often find it hard to give detailed descriptions of their knowledge and how they use it Indeed the process of closely questioning an informant can interfere with his own perceptions of what he does This is because much knowledge is tacit that is it has been learnt through observation and experience and is understood but is not generally expressed In a similar fashion the status assumed by the researcher in the study community will also influence the elicitation process since all attempts to reduce social and intellectual barriers and improve understanding will enhance knowledge elicitation and co operation If the researcher assumes the role of learner his reception by expert informants will differ markedly to the one he may encounter if he presents himself as scientist or planner or otherwise assumes an elevated status The role of communication skills both in researcher and informant is an essential element in knowledge elicitation and is of particular significance in cross cultural work see Werner and Methodology 13 Chapter Two Knowledge Elicitation ochoepfle 1987a amp b The familiarity and skill with which words are used to express concepts and procedures will affect the quality of knowledge elicited through interview Although people identified for interview may be experts it
212. n increase in availability of private_fodder causes an increase in amount of animal_fodder anincrease in amount of animal Fodder causes an increase in number of animal anincrease in scale af migration of Farmer causes a decrease in availability of Farm labaur a decrease in availability of Farm labour causes a decrease in number of animal a decrease in number of animal causes a decrease in availability of animal manure a decrease in availability of animal manure causes a decrease in fertility of sail a decrease in amount of animal fadder causes a decrease in amount of crop residue an increase in scarcity of firewood causes a decrease in amount of crop residue anincrease in amount of crap residue causes an increase in amount of mulching of stubble cultivation of looge soll causes an increase in production of crop if the amount of compost is high cultivation of loose sail causes a decrease in production of crap if the amount of rainfall is very hi A cultivation of sandy soil causes an increase in production of crop if the amount of compost is high gt cultivation of sandy soil causes a decrease in production of crop if the amount of rainfall is wer hi a decrease in depth of soil causes an increase in rate of sail erosion an increase in amount of soll erosion causes a decrease in production of crop the system season is winter causes the amount of rainfall ts low a decrease in amount of rainfall causes an increase i
213. n moisture stress of soil Diagram Selection Type All Statements Causes Effecta Navigate Pint Statements Figure 7 15 Statements dialog box From the Statements dialog box it is possible to check all the details of a statement the sources the formal terms any definition of those formal terms any synonyms and any memos and to edit that statement Highlighting the relevant statement and selecting Details will allow you to check all these details without the danger of making any inadvertent alterations Highlighting the relevant statement and selecting Edit permits you to edit the statement and all its appended details Figure 7 16 ee Edit statement 57 details Statement Ma 57 KbMame sal Snurce s Farmers 1337a Cave Natural Language BE cultivation of sandy soil causes an increase in production of crop 4 Snurces F the amount of compost is high 4 k Farmal Terms Memo Formal Language Statement achon cultivation sandy soil causes Twa ath value crop praductian increase Syntax Check IF att_valelcompost amount high Translate 1 F Figure 7 16 The Edit statement dialog box Knowledge Acquisition 59 Chapter Seven Software manual for AKT 7 4 3 a Adding definitions to formal terms It is important that all formal terms remain as unambiguous as possible However different users may have a different understanding or concept of the same term For example alley croppi
214. n two or more topics use and to link the topics The Topic Search Option box shows what combination of object subobjects and superobjects was used to create the topic This cannot be altered from within the Topics dialog box To alter the combination you must press Details Edit and revert to the Boolean oearch dialog box and alter it there Figure 7 2 is an example of combining two topics using OR The two topics chosen were ooilColour and SoilTexture The Boolean Search String at the bottom of the dialog box gives the two topic names chosen Once the selection is made press Search and the Search Results dialog box appears Figure 7 73 Knowledge Acquisition 85 Chapter Seven Software manual for AKT xh ee Search results soil knowledge base i Oh x Topic search option Total number of statements Details i object Selected Statement fl subobiects D etails E dit Natural Edit 8 superabjects Saillolour Nw Soils Boolean options Sol esure peice textureErasion ND o Enos the fertility of black soil is high TES gt the water_holding_capacity of black soil is high the fertility of loose soil is low the fertility of sandy soil is low the amount of erosion of red soil is high the amount of erosion of loose soil is high the rate of leaching of red soil nutrient is low the rate of leaching of sandy soil nutrient is high the amount of erosion of sandy soil is
215. ncorporating pictures and diagrams into the knowledge base CHAPTER ELEVEN INCORPORATING PICTURES AND DIAGRAMS INTO THE KNOWLEDGE BASE In AKT 5 there is the option to incorporate pictures and diagrams into the knowledge base The Atwima knowledge base below shows what can be done Figure 11 1 shows the Welcome Page with a thumbnail picture This picture can be enlarged by double clicking on the image with the left mouse button Figure 1 1 2 m Y Yelcome to the atwima knowledge base E Picture emia Farmers knowledge of soil fertility and E of this knowledge base Women farmers discussing different weed species Whatthis knowledge base is about Soil fertility management z soil classification weed management and cocoa shade trees m knowledge base was developed by Eie This knowledge base was originally Acknowledgements Reginald Agbo for invaluable help talking Figure 11 1 Welcome Page of the m 1 z The TEENE TEI with a Atwima knowledge base with the description of the image thumbnail picture By pressing Further Details the second part of the Welcome Page appears Figure 11 3 at the bottom of which is a button Pictures Diagrams Selecting that button a new dialog box appears Figure 11 4 from which you can select one of the pictures or diagrams on the menu by highlighting one and pressing Select me Details of the atwima knowledge base E CH Fictures diagr
216. nd cocoa and press Save The topic details dialog box appears showing the Boolean Search String that makes the topic and allowing you to write a description of the topic in the Description box Press Save once more you should get a message saying that the topic has been saved Now go to the main menu and select KB Topics Select your new topic staple crops and press Select and then Search All the statements linked with that topic will appear Press All Statements in the Diagram Selection Type to get a visual idea of all the causal statements involved Tutorials 153 Chapter Thirteen A quick sightseeing tour around AKT Closing a knowledge base and finishing off Before you finish using the knowledge base you must save your knowledge base if you wish to save the changes you have made Save is via the main menu KB Save Kb or if you wish to keep both versions KB Save KB as When you have saved your knowledge base close the knowledge base KB Close KB and close AKT by going to the main menu File Exit AKT ASSIGNMENT Create two new topics exploring what women know about trees and what men know about trees Compare the two knowledges and suggest reasons for the differences similarities between them Big Hint Start off in the Boolean Search selecting Sources If you press Details for each source you will see if the source is male of female Link the sources together with OR but link the tree
217. nd keeping the button down drag the statement to the side until the statement below is fully visible 8 2 4 e Hiding labels Whilst it is possible to move the labels around it is obvious from Figure 8 9 that a diagram with all the natural language statements visible can rapidly become impenetrable Not all the labels may be necessary the nodes being self explanatory or the processes already well known and thus not requiring notation In order to improve the clarity of the diagram it is possible to turn off on the labelling for a selected link Select Label from the Show Hide box on left hand side of the diagram screen then press the left hand mouse button down on the first node and holding the button down drag the mouse down to the end node and release Figure 8 10 demonstrates how judicious use of the Label switch off function can render a diagram much clearer Knowledge Acquisition 100 Chapter Eight The diagram interface p Idi fertilizer l site ang een govemment_subsid steepness En an increase in the steepness of site causes an increase in the rate ot Soll erosion intensity fertilizer soil emp price erosion cultivation rate an increase in the amount af f raintall causes an increase in tt a decrease in the price of an increase in the rate of zoil rate of Soll erosion tertilizer causes an Increase In Erosion eauses an increase in the the usage of fertilizer amount at zai erozion sail fe
218. ne beginning with 9o is a comment and not an executable part of the tool Thus choose a topic from all the loaded Kbs ignore Kb parameter tells you that the next step will instruct the program to permit you to choose any one topic from all the Using Knowledge 132 Chapter Ten Creating your own tools available topics in the loaded knowledge bases In the following step by step analysis of the tool these descriptions have been removed b Each primitive or tool may have parameters which can be any combination of input and output parameters The output parameter can contain a result which is returned as the output from the tool or it can in turn be used as an input parameter to another primitive or tool later in the definition Ri NOTE An input parameter is one where the primitive or tool expects the parameter to be specified before starting the tool An output parameter is one where the primitive or tool determines the value and returns this value as the output at completion of the tool Here goes que Mill Take one knowledge base topics Topics list select Topics Please choose a topic Topic The first step enables the user to specify the topic that he wishes to investigate The topic may come from any of the loaded knowledge bases as the knowledge base parameter is left unspecified This primitive is from the Miscellaneous category and its generic form is knowledge base Type Kb Result In
219. new tool line by line you can instead select Test for a trial run of the tool As in Trace the same dialog boxes appear the first one specifying the input parameters see above Figure 10 16 the second one requesting the input parameters to be entered see above Figure 10 17 After pressing the Continue key the Save Kb As dialog box appears requiring you to enter a name for the new knowledge base Once you have chosen and entered a name for the new knowledge base press Save The next dialog box to appear is then the Tool output screen giving all the statements containing soil Table 10 1 lists all the statements that appear in the Tool output screen Table 10 1 Statements containing the formal terms soil in the knowledge base treefodd retrieved by the tool saveStatements ToKB Kb Term Results of running the tool Call saveStatements ToKb 2 on 22 5 2001 at 10 40 38 Kb treefodd Term soil This is a numbered natural language version of the statements 441 an increase in rate of erosion of soil causes a decrease in fertility of soil 442 an increase in rate of movement of soil causes an increase in rate of erosion of soil 451 the soil condition is moisture stressed causes the crop condition is moisture stressed 452 an increase in dampness of soil causes a decrease in vigour of crop 453 an increase in dampness of soil causes an increase in rate of infestation of crop pest 454 an increase in dampness of s
220. ng may suggest to some a system where the tree component is made up of a single or multiple row of trees whilst others envisage a system of dense hedgerows For this reason it is useful to be able to define exactly what is meant by the term in the context of a specific knowledge base In order to add definitions select Formal Terms in the Edit statement dialog box Figure 7 16 above and the following screen appears Figure 7 17 The Statement Formal Terms dialog box displays two lists the first headed Statement Formal Terms gives a list of all the formal terms within that particular statement By highlighting one of the terms that term s type i e object process action attribute value link or comparison will be displayed in the Type box The second list headed Formal Terms gives a list of all the formal terms within the knowledge base This serves as a reference and should be consulted so as to avoid unnecessary use of synonymous terms In order to define any of the terms highlight the required term and select Details The Formal Term Details dialog box will appear Figure 7 18 The Formal Terms Details dialog box enables you to e define the term by filling in the Definition box e check whether the term has any synonyms e check in which statements the term has already been used by selecting Show use in statements and e check whether the term already appears in an object hierarchy
221. nt to remember that judging reliability of statements subjectively by the knowledge base developer is difficult It is best to opt for the rule of thumb consider true unless proven wrong Box 1 An example of apparently inconsistent unitary statements In an investigation into forest gardens in the Kandy district of Sri Lanka Southern 1994 the following statements were given by the same informant on different days Vegetable diseases are reduced in the shade Abeysinghe 21 4 92 Disease problems are not influenced by the degree of shade Abeysinghe 26 4 92 However after returning to the source to clarify this apparent contradiction it became clear that the second statement related to a conversation about a part of the garden where vegetables were not grown Thus by appending the conditions in which the statements were relevant they were no longer contradictory Inconsistent knowledge should in principle be resolved by one of the above mechanisms Conflicting statements may frequently not be resolved under such circumstances the two unitary statements may be flagged by attaching a Memo to both statements stating that these are alternative views Automated reasoning tools are useful for identifying some types of inconsistency for example the inconsistent att value statements and the inconsistent causal statements tools provided in the macros Methodology 44 Chapter Five Knowledge base management 5 3 3 COMPLETENESS
222. nt topics from a formal knowledge base see Chapter 7 provides a means of dividing a knowledge base into subsets effectively creating smaller sets of Knowledge with which to reason It is better to create fewer knowledge bases covering a broader range of knowledge rather than many small knowledge bases This reduces repetition of core knowledge amongst knowledge bases However ensuring consistent and unambiguous use of terms coherence and completeness becomes an increasingly demanding task as the knowledge base grows in its breadth of coverage Furthermore too large a knowledge base is unwieldy implementational constraints such as computer memory and speed of processing have an increasing impact as the knowledge base grows in size It is necessary to define clear boundaries for a knowledge base and to represent unrelated knowledge in different knowledge bases in order to ensure the creation of tractable results For example in the Nepalese case study three discrete topics were identified on the basis of the objectives given above and in consideration of the domain that had to be investigated in order to generate a comprehensive record of the explanatory ecological knowledge used by farmers in managing their farmland tree fodder resources These topics were e the propagation of tree fodder resources e tree crop interactions and the selection and e evaluation of different fodder for livestock As a result three knowledge bases were creat
223. ntly shallow or deep and some knowledge of the speed of decomposition of leaf litter which occurred above ground and so could be observed As trees were regularly lopped for fodder a number of issues pertinent to practical management arose with respect to species differences in root systems characteristics and the effects of different lopping strategies on root development and competitiveness which farmers were hitherto unable to address The rigorous approaches to representation and analysis which are used in AKT have made it possible to explore the comparability and compatibility of Knowledge from different sources Application of the grammar across a range of agroforestry research programmes has shown that ecological knowledge can be made comparable across sites and cultures including the divide between scientific or professional knowledge and the ecological Knowledge held by farming communities see Box 3 and Box 4 1 7 2 THE KNOWLEDGE BASE AS A RESOURCE Creating a knowledge base involves a significant investment of time particularly when many people have to be interviewed The product therefore should be a resource that is suitable for many purposes AKT has been designed in a way that should allow development professionals within research institutions to make routine use of a set of centrally maintained topic specific or problem specific knowledge bases for a range of purposes and to improve the content of the knowledge bases
224. o Figure 8 25 New Statement dialog box From the New Statement dialog box it is possible to edit the Formal Language Statement for example changing causes1way to causes2way or even changing the various formal terms The source can also be modified by selecting Sources and a memo can be attached to the statement by selecting Memo Itis also in this dialog box that any conditions attached to the statement may be added In order to save the statement press SAVE If you press CLOSE or the close box X before pressing SAVE the statement will be lost although the nodes will remain on the screen If no conditions were added in the New Statement dialog box once SAVE has been pressed the following message then appears Figure 8 26 asking whether the statement should be saved without a condition In principle unitary statements are generally more useful when qualified by conditions It is not possible to enter conditions diagrammatically therefore any conditions have to be entered in the formal language statement IF box In this simple example there are no conditions so No is selected Rib Basil RETE x 9 Are you sure vau want to save this statement without a condition 7 Figure 8 26 Message that appears when saving a statement without any conditions Then a message will appear for each new formal term you have created e g Do you wish to create a new formal terms defore
225. o any preconceived ideas which helped formulate the objectives in the first place An appropriate balance may best be achieved by making the purpose of the Knowledge base the objective rather than the actual structure and content of the knowledge base the objective For example research in Nepal was intended to Document explanatory ecological knowledge used in decision making by farmers in managing their farmland tree fodder resources in order to better inform national and regional research efforts Subsidiary objectives for the same research could be Comparison of the local knowledge with scientific knowledge These objectives for using the contents of the knowledge base s provided a framework for its creation The iterative nature of the process of knowledge base creation allows the reassessment and modification of objectives as the knowledge base develops 3 1 2 BOUNDARIES OF THE KNOWLEDGE BASE The second stage in the process of preparation is to define the boundaries and contents of the proposed knowledge base The boundaries must be defined with reference to the stated objectives Methodology 17 Chapter Three Preparation for knowledge base creation The Knowledge base is an arbitrary unit Two knowledge bases may be merged into a single knowledge base or a single knowledge base may be split into two Furthermore different sets of knowledge may frequently be needed for different tasks The mechanism for developing differe
226. oes not make use of the full range of combinations possible with the formal grammar so some types of statement attribute value statements and comparison statements can be entered only through the text interface Nevertheless while diagramming is less expressive than text it allows creation of coherent knowledge bases by less experienced users The diagramming and text based interfaces can be used interchangeably which allows the user greater flexibility There is also a facility for the automatic diagramming Methodology 5 Chapter One Overview of selected sets of text entered statements to gain an overview of selected parts of the knowledge base 1 5 REASONING WITH KNOWLEDGE BASES A knowledge base is developed in AKT in order to create a synthesised report of the current state of knowledge on a defined topic The knowledge may then be used for a range of reasoning tasks Some examples of different user level reasoning tasks are listed in Table Toe Table 1 1 Some examples of user level reasoning tasks Generating synthesised reports of the current state of knowledge local scientific or combined on defined topics as a resource for extension and planning Exploring the knowledge base in order to identify discrepancies between knowledge held by a local community and scientifically verified information Correlating scientific information with local description to broaden the range of applicability of research results Facilitating r
227. of Effect Value in the Parameters box If it is completed in exactly the same manner as in Figure 8 23a it will give the statement a decrease in rate of evapotranspiration will cause deforestation which is clearly nonsense As soon as OK has been selected from the Choose Link dialogue box Figure 8 23a the Information Source dialog box appears Figure 8 24 This is identical to the Information Source dialog box that appears before entering a unitary statement via the main KB menu See Chapter 7 4 2 and must be completed in exactly the same way if the statement is to be accepted egg Information Source Please select information source Selected Source Po Type Interview amp reference 5 nurces mone t nterview C Reference Figure 8 24 Information Source dialog box Once the Information Source dialog box has been completed as in the manner described in Chapter 7 4 2 the New Statement dialog box immediately appears Figure 8 25 giving both the formal language representation and the natural language representation of the nodes and link created in the diagram interface Knowledge Acquisition 114 Chapter Eight The diagram interface ug New Statement new kb Statement Ma 1 KB Mame nev Source s manual 1 338a Cave Natural Language the process of deforestation causes an decrease in the rate of the process of evapatran Close Sources Formal Terms Mem
228. of Fadder tree position i onie bita above last year cut causes the fodder tree new_ 1164 lopping of Fadder tree causes an increase in number of new shoot if the branch node number iz i Diagram Navigate Print Statements Figure 7 85 Search Results dialog box for the formal term new_shoot If you select Yes then the following Save output in file screen will appear Figure 7 87 me Save output in file ms Print 2 x Printer Save in cx Laxman HE Name Outside F5 laser Status Default printer Ready Type HP LaserJet 4000 Series PCL 6 Where SLURCHShp4000tn1 Comment Print range Copies All Number of copies fi Pages from tJ aell Collate 3 alate 4 C Selection save as type Listing files doc txt m Cancel OK Cancel Figure 7 87 Saving the Search Results statements Figure 7 88 Print dialog box to a file This allows you to save the text as a text file in a directory and folder of your choice Once you have named the file and saved it in the correct place press Save If you decide not to save the file and press No in Figure 7 86 above the printer details dialog box will appear allowing you to change its properties before printing Knowledge Acquisition 91 Chapter Seven Software manual for AKT 7 13 1 PRINTING IN LANDSCAPE If the statements are particularly long it may be better to print out the statements in lands
229. oil causes a decrease in crude fibre content of tree leaf 455 the dampness of soil is low causes the soil condition is moisture stressed 456 a decrease in fertility of soil causes a decrease in vigour of crop 457 a decrease in temperature of soil causes a decrease in vigour of crop 458 a decrease in temperature of soil causes a decrease in rate of germination of crop seed 512 shading causes an increase in dampness of soil 513 shading causes a decrease in temperature of soil 517 the land site quality is malilo causes an increase in fertility of soil 518 a decrease in quantity of manure causes a decrease in fertility of soil 527 an increase in effect of shading causes an increase in dampness of soil 539 a decrease in rukhopan of tree leaf causes an increase in fertility of soil 556 an increase in competitiveness of fodder tree causes a decrease in fertility of soil 568 an increase in soil binding ability of fodder tree causes a decrease in rate of movement of soil 5 3 a decrease in competitiveness of tree causes an increase in fertility of soil 5 4 a decrease in difficulty of ploughing of crop land causes an increase in fertility of soil 630 the moisture content of shaded cropland soil is greater than open cropland soil if the system season is hiudae crop End saveStatements ToKb 2 on 22 5 2001 at 10 41 28 Using Knowledge 143 Chapter Ten Creating your own tools 10 4 5 COMPLETING THE TOOL Either before or after sele
230. ol one line at a time or Test to run the whole tool at once In this example we will look for all the statements containing soil in the treefodd knowledge base and save them as a separate knowledge base called treesoil 10 4 4 a The trace key If after following the example of the new tool above 10 4 3 you select Trace the same dialog box as Figure 10 16 above will appear in which the input parameters are specified Tick both and press OK Then another dialog box appears requesting you to enter the input parameters Figure 10 17 For this example the parameters are entered as follows e Kb Soil e Term soil and erosion Then press Continue The following screen appears Figure 10 168 Using Knowledge 141 Chapter Ten Creating your own tools mg Please specify input parameter s E E step_dialog Kb BODY oftool saveStatements ToKb Kb Term statements search treefodd soil object allListFormalStatements statements save treefodd ListFormalStatements statements convert numbered treefodd ListFormalStatements TranslatedStatements show This is a numbered natural language version of the statements nl Continue Cancel Figure 10 17 Specifying the show TranslatedStatements input parameters for use of the saveStatements ToKB Kb Term tool PARAMETERS treefodd soil ListFormalStatements TranslatedStatements Figure 10 18 Using the Trace option Each time you press Step the highlighte
231. omparison statements 0 of which O are conditional Number of link statements 3 of which O are conditional Remaining within the Systems Tools category go to Knowledge Exploration 2 The tool species report 2 extracts information from the knowledge base about a particular species Press Run An input parameter dialog box appears requesting the name of the knowledge base and of the species to be extracted Enter the name of your knowledge base and enter crops in the species box Then press Continue You should get the following output Kb slash and burn opecies crops INFORMATION SHEET FOR crops HIERARCHY plants vegetation Crops ATTRIBUTE STATEMENTS none CAUSAL STATEMENTS harvesting of crops causes a decrease in level of soil nutrients COMPARISON STATEMENTS none LINK STATEMENTS Species in this context can mean any object in the knowledge base Tutorials 165 Chapter Fourteen Tutorial in creating a simple knowledge base none CONDITIONAL STATEMENTS none DERIVED STATEMENTS the erosion of soil rate is minimal if crops covers soil the rate of erosion of soil is high if crops not_covers soil burning of site causes removal of crops removal of crops causes an increase in level of insolation of soil This tool not only tells you all about the selected species in this case crops but it also gives you all the statements derived via the object hierarchy as well S CLOSING YOUR KNOWLEDG
232. ons on which this program is based Information about the AKT version being used Quote for any problems or queries Eg AKT no knowledge base loaded File KB Diagram Tools Help Formal Grammar Tool List Publications About AKT Figure 12 1 The Help menu 12 1 THE FORMAL GRAMMAR The formal grammar in Figure 12 2 is exactly as in Table 4 1 in Chapter 4 It is available via the Help menu so that when formalising unitary statements you can quickly refer to it to see if the format of the unitary statement you are proposing is valid If the proposed formal statement does not conform to any of the structures listed in the formal grammar it is not valid and AKT will not accept the statement ge AKT s formal grammar FormalSentence gt Statement if FormalConditions FormalSentence gt Statement statement gt Cause Causes Effect where Causes is an element of the set causes way causes wv statement gt Attribute statement statement gt not Attribute Statement statement gt link influence Thing Thing statement gt link Link Object Object statement gt link Link Processo PracessBit statement gt linkiLink ProcessBit Object statement gt comparisan Atribute Object Comparison Object FormalConditions gt FormalConditions and FarmalCanditians FormalConditians gt FarmalConditions or FormalConditions FormalConditions gt Statement FormalConditians gt ActianBit Fo
233. ools Help Diagram 1 r Add node Object Process Action Add Link Figure 8 22 Partial view of the main diagram screen with the two nodes In order to link the two nodes the Link button on the left hand side of the diagram screen is selected Figure 8 22 then the left hand mouse button is pressed down on the deforestation node and released on the evapotranspiration rate node When the two nodes have been connected in this way the Choose Link dialog appears Figure 8 23 In this case the causes1way is the correct selection In the Effect Value box decrease should be typed Knowledge Acquisition 113 Chapter Eight The diagram interface me Choose Link me Choose Link Choose type of link and enter appropiate values Choose type of link and enter appropiate values Link Type Dk Link Type m causes way e pam causes way causeszway Canes Cancel causeszway Parameters Parameters Ha D Figure 8 23a Choose Link dialog box Figure 8 23b Choose Link dialog box if the cursor is dragged in the wrong direction It is important to drag the cursor in the right direction between the two nodes i e in the direction of the causal flow f you drag it in the wrong direction i e from evapotranspiration rate to deforestation a Choose Link dialog box as in Figure 8 23b will appear with Cause Value instead
234. ople and documents as the sources of the knowledge A store called a knowledge base of explicitly recorded knowledge statements or facts is developed When a knowledge base has been created on computer there is an explicit and accessible record of the knowledge that can be used later to help in making decisions for and during development of research and development programmes Unlike many existing expert systems the KBS approach is not intended to provide definitive or prescriptive answers to questions but to ensure that decisions are based upon consideration of relevant information The approach comprises a methodology for acquiring knowledge and storing this explicitly recorded knowledge and an associated computer software for creation and use of knowledge bases The toolkit is called AKT which stands for Agroecological Knowledge Toolkit and can be used to provide various levels of support to suit different needs in knowledge analysis and decision making Although the methodology was initially developed for agroforestry domain it can be applied equally well in other disciplines This first part of the manual provides an overview of the approach and of the thinking behind it The manual as a whole provides guidelines on how to apply this approach when planning agroforestry research and extension 1 1 BACKGROUND AND OBJECTIVES Agroforestry either involves farmers growing trees or shrubs in various productive or environmentally protective nich
235. options C subobjects allaichi_bari allelopathy object C superobjects altitude C subobjects always superobjects Number of terms B1 z CERE Captures all the statements about the two types of field cultivated by the local farmers Boolean Search String ed 1 k Figure 7 67 Creating a topic Statements Figure 7 68 Filling in the Topic details dialog box If the search string incorporates hierarchic objects then the Search Mode will allow you to specify further search criteria Once you have filled in all the details press Save A message will appear Figure 7 69 confirming that the topic has been saved CE AN The topic has been saved Figure 7 69 Message confirming that a new topic has been saved Once you have pressed OK the screen reverts back to the Boolean Search dialog box 7 11 2 MANAGING TOPICS To manage topics already created it is necessary to select Topics from the main KB menu The following dialog box then appears Figure 7 70 Knowledge Acquisition 84 Chapter Seven Software manual for AKT sus YW IN PROLOG xc Topic search option ry Y imeem i object 2 Are you sure you want to delete this iem famners crop idi 9 subobjects farmers fodder i superabjects scientists Boolean options scientists crop scientists fadder Select tree fodder Ires crop Figure 7 71 Message to confirm that the alias is to be deleted Search Save as kb
236. orange Alternatively green orange and black caterpillars might be classified as being poisonous caterpillars such that Feeding leaves to livestock causes sickness if there are poisonous caterpillars on the leaves Considering this unitary statement in relation to other statements may also demand consideration of linkages for example are there statements which describe the consequences of a decline in the health of livestock Apparently contradictory statements may be identified and resolved For example does the statement that Leaves of fodder trees that are attacked by caterpillars do not cause sickness in livestock mean that caterpillars do not cause sickness or does it mean that the leaves of those trees that are attacked by caterpillars do not cause sickness provided that there are no caterpillars on them At this juncture consistency of use of terms can be ensured The term livestock is in the current context defined in the object hierarchy as cows goats and buffalo Do all the statements that use the term livestock refer to all three of these or should some be replaced for example with cattle or milking livestock i e cows goats or buffalo that are currently lactating Precise use must be considered in terms of precise definition The term feeding is used in this statement It may be that this term is defined as meaning the action of providing fodder for livestock that are stalled This m
237. orrespondence of linked pairs of nodes If two nodes connected by a link represent useful knowledge there will be a correspondence to a meaningful English sentence This sentence will in fact comply with the definition of a unitary statement see Part 4 1 2 Where this correspondence does not occur either one or both nodes or the link must be inappropriately labelled stream turbidity rate of soil erosion increase causes increase Methodology 32 Chapter Four Knowledge representation can be read as An increase in the rate of soil erosion causes an increase in stream turbidity which makes sense in English rate of predation increase causes decrease would read as An increase in the rate of predation causes a decrease in rats This is understandable but incomplete To formalize this statement one needs to be clear what it is about the rats that decreases in this case it is the number of rats or their population size which decreases not the rats themselves Thus this should be explicitly stated by re labelling Rats as Rat population size or Rat number The node rate of predation is also incompletely labelled and clearly refers to the rate of predation on the rat population It can be argued that this can be assumed from the context of the diagram but where a diagram is created as a means of generating a coherent kn
238. ource Ea AN Source appended to Statement AN Source removed from Statement Figure 7 21 Message confirming that a Figure 7 22 Message confirming that a source has been appended to a statement source has been detached from a statement Knowledge Acquisition 61 Chapter Seven Software manual for AKT Ri A statement must have a source If there is only one source attached to the statement it is not possible to detach it 7 4 3 c Appending Memos otatements may need certain clarifications which cannot be expressed in the formal language and therefore have to be appended to the statement in the form of a memo For instance in the example given here of a new statement Cultivation of sandy soil causes an increase in production of crop if the amount of compost is high Figure 7 14 above it may be appropriate to list in the memo field what the compost is made of It is better to put the explanation here rather than in the Formal Terms dialog box because the type of compost referred to may differ from statement to statement and the Memo dialog box is attached to the individual statement To add a memo select Memo from the Edit Statement dialog box and the following dialog box appears Figure 7 23 S WARNING After writing a new memo you must press Save If you ms Memo attached to statement 39 KB name soilkb Delete Close a press Close after typing in a new memo you will lose the memo
239. owledge base this cannot be assumed Predation of other species may occur elsewhere in the knowledge base which can probably not be assumed as being of the same nature as and therefore equivalent to the predation of rats Therefore the first node should properly read Rate of predation on rat population 4 4 3 d Labelling of links lt will often be possible to express the meaning of a particular link in different ways However using different terms for the same concept reduces the comparability of the resulting diagrams particularly given that differing terms for the same concept will rarely be exactly equivalent Fungal wilt causes yield loss is similar to Fungal wilt results in yield loss and Fungal wilt leads to yield loss and not very different from Fungal wilt is followed by yield loss which might be restated as Fungal wilt happens before yield loss The above example illustrates the importance of ensuring a consistent use of terms both within a diagram and between diagrams in order to attain unambiguous comparability of links 4 4 4 SUBSETS OF DIAGRAMS Experience in the creation of diagrams as a means of producing coherent knowledge bases suggests that diagrams containing more than 40 nodes tend to be increasingly difficult to interpret This is in part the result of the balance that must be achieved between the size and therefore legibility of nodes and text associated with links and standard paper or computer screen s
240. parameters to the executable shortcut as described on page iii How to Install AKT at the front of this manual C3 1 get the error message 1 error s during compilatiow when trying to load a knowledge base Is often happens when a knowledge base has been emailed to you The reason for it is obscure but it is easy to fix Open Wordpad or any other text program Open your knowledge base within that program Scroll down to the very last line of the knowledge base Make sure that the last line has a full stop at the end Then press carriage return 1 Save the file and then close it Open AKT and try to open the knowledge base It should now work C3 My knowledge base opens but all my statements are missing There are three possible reasons for this 1 You saved all your statements but did not save your knowledge base using Save KB from the main KB menu If you do not save your knowledge base at the end of a session you will lose all the work you have done since you last saved the knowledge base properly 2 You have changed the name of your knowledge base outside the AKT program using Windows Explorer for example You should only change the name of your knowledge base from within the program by selecting Save KB As from the main KB menu To get the statements back revert to the old knowledge base name 3 You are trying to open a knowledge base in an earlier version of the program than it was created in You can open a
241. pear Figure 7 32 is of the Object Hierarchy dialog box for a newly created hierarchy with no objects attached me Object Hierarchy treefodd kb KB Name treefodd Hierarchy Mame Soi type selected Object Soil_ type Objects in Hierarchy Hierarchy Structure Sail wpe Super byects Chose Object Details Selected object Append to Detach Immediate 5 ub byects Move Copy none View Tree Object Figure 7 32 The Object Hierarchy dialog box of a newly created object hierarchy To add objects to a hierarchy select Append to The resulting screen Figure 7 33 will offer you a list of all the objects in the knowledge base Highlight the desired object under the Objects list and select Append The message Object appended to Hierarchy will then appear Figure 7 34 and the object will appear as an Immediate SubObject of the hierarchy root es Append Object treefodd kb KB Mame treefodd Hierarchy name Soil_type Append to Sall tupe Object black sail me Sppend Object AN Object appended to Hierarchy Close _Details_ object has been appended to the object hierarchy Figure 7 34 Message confirming that the Figure 7 33 Selecting an object to append to an object hierarchy Any number of objects can be appended to the object hierarchy in this way appending them one at a time The objects that appear in the object list Figure 7 33 above are
242. pping the diagram To restore the current diagram select the Refresh button Knowledge Acquisition 101 Chapter Eight The diagram interface 8 3 CREATING SUB DIAGRAMS 8 3 1 SHOW PATHS Even in such a relatively small knowledge base as soil the diagram soon becomes crowded and it is sometimes difficult to see if or how nodes are connected In the example below it was required to ascertain whether there was any relation between the nodes field steepness and crop production The two nodes are highlighted Figure 8 11 by double clicking of the right mouse button which turns them green and then select the Show Paths button Ei msi as NEP DE Figure 8 11 The complete diagram of soil knowledge base with nodes field steepness and crop production highlighted A new diagram appears showing the pathway between the two nodes Figure 8 12 File KB Diagram Tools Help 101 Title Diagram 101 Memo Object Attribute r Add node Node Link r Show Hide Label Select Diagram ESI Figure 8 12 New diagram screen showing the pathway between field steepness and crop production In some cases the new diagram might be too big to fit into the screen without using Zoom Out to reduce it In such circumstances it is possible to rearrange the diagram by selecting a node with the left hand mouse button then holding it down dragging the node across
243. presentation because some statements which cannot be represented directly in the formal grammar for example temporal statements can be represented using the other existing structural types 4 2 3 d Creation of the formal statement Formal statements may be of one of five types a causal statement a comparison statement a link statement an attribute statement or a negative attribute statement see Table 4 1 oome unitary statements may be captured by more than one formal statement type However the different types have a differing utility in reasoning with the knowledge base In general causal statements are the most useful Any type of statement may additionally have conditional information attached 4 2 4 STATEMENT TYPES 4 2 4 a Attribute Value statements The most basic form of statement is the attribute value statement An attribute value statement is descriptive it describes an object or process or action An attribute value statement for an object takes the form att value Object Attribute Value e g att value tree height tall An attribute value statement for a process takes the form att value Process Attribute Value e g att value process leaf decomposition rate slow Entire formal unitary statements can be captured as attribute value or negative attribute value statements where the statement consists of a single object or process or action and information about the value of an attribute of that object or proc
244. puter TABLE OF CONTENTS FOREWORD HOW TO USE THIS MANUAL sss Immer hrs HOW TOJINSTAELE AKI D 3 duce voca ao Ex Poi e Er Apu goi TETE E IKE e ads TABLE OF CONTENTS rosae ric oo EN EaSEEE TEE CHE Ts Daalor n o equo En SEM Un xebaan veia echa E RIDE CHAPTER ONE OVERVIEW deserens o sustesoe na et REO cu IR aS Vid uU ME E ERAN Ee oUK a ET EE E 1 1 BACKGROUND OF OBJECTIVES prorata a ortu Esas moy a SET ote R EE ESbr e TEES 1 2 WHAT DO WE MEAN BY KNOWLEDGE 0 cece cece cena HII 1 3 KNOWLEDGE BASE CREATION as etra reete Y au eg ee eo E SP PFEEPkR heu ERR PvE TERI 1 4 KNOWLEDGE BASE STRUCTURE sss see eese essen nnns 141 STATEMENIINTEREAGE oti ipae Er rieenEeiER Ur D EE 142 DIAGRAM INTERFACE meciria rn a E eU esed eee o doa use sede Do ao Seb E eR TRE 1 5 REASONING WITH KNOWLEDGE BASEG ccc ccc cece cece ee eee ee eeaeeeeaes 1 6 APPLICATION OF KNOWLEDGE BASED SYSTEMS APPROACH TO AGROFORESTRY RESEARCH AND EXTENSION esee Le THEUTIELITY OF THE APPROACH ii cst 2 isa eue duras rM eec ep eame aicase leads eus 1 7 1 THE EXPRESSIVENESS OF THE AKT APPROACH AND IMPEEMENTATIO IN s ius deducta be RE en Regu Ried o ERE e ERU E ead Re incos 1 7 2 THE KNOWLEDGE BASE AS A RESOURCE cc ccc cece cence ees 1 7 3 THE UTILITY OF THE REASONING MECHANISMS 1 7 3 a Property inheritance cccc cec
245. r Figure 9 2 Using Knowledge 121 Chapter Nine Reasoning with AKT tools Eg Tool Details formal_term Kb Term Type Result Tool Formal Term Current Tool none Description Returns information of specified type about a formal term Type attributes returns list of all attributes possessed by an abjectterm Test Type hierarchies returns list of all hierarchies in which the objectterm is used Wace Paramete Input Kb Term Type Output cose Tool Definition Tool Name Parameters agitan WEEE farmal term Kb Term Type Result ree a _Browse Tools Tool Body Note Must finish with a full stop then a new line __ Print Tool Figure 9 2 Tool Details dialog box of the primitive formal_term Kb Term Type Result The dialog box title shows the tool category in this case Formal Term and the current tool file if a user tool file is loaded in this case there isn t Taking the output dialog box apart bit by bit you have Description Here the function of the tool is described together with a relevant example Below is the information provided in the Description box for the tool formal_term Kb Term Type Result Returns information of specified type about a formal term Type attributes returns list of all attributes possessed by an object term Type hierarchies returns list of all hierarchies in which the object term is used Type synonyms returns list of all the synonyms use
246. racts unitary statements in which either the specified object its children and descendants its parent or ancestors all the way up the hierarchy tree are used The collection of statements displayed as a result of a Boolean Search will assist in the interactive evaluation of the knowledge base contents but it is worth noting that all of these search facilities can be invoked by one or more of the primitive tools see chapter 9 Knowledge Acquisition 83 Chapter Seven Software manual for AKT 7 11 TOPICS 7 11 1 CREATING A TOPIC It is possible to save any combination of search criteria to gather all the information about a particular topic within a knowledge base To create a topic first select your search criteria for the Boolean Search String as described above 7 10 1 Then enter a topic name in the Name of new topic box in the Boolean Search dialog box Figure 7 67 and press Save The ensuing menu Topic details will permit you to add a description of the topic Figure 7 68 as Boolean search treefodd ms opic details field tppe Display Kb terms af type Mame af new topic formal terms amp sources E topic field type List of existing terms in Kb Save search selection af the specified type Een Boolean Search String L Joshi 19955 Livestock Scientists 1394a Plant Scientists 1 384a Salma farmers 1994a Salma farmers 19958 Details Close Search Made f object ie search
247. rmal Conditions gt PracessBit AttributeStatement gt at_value Object Attribute v alugl Attribute statement gt att value FrocessBEit Attribute salue Figure 12 2 The formal grammar as it appears in the Help menu Help 147 Chapter Twelve The help facility 12 2 THE TOOL LIST The Tool Information dialog box Figure 12 3 is simply an alphabetically ordered list of the tools supplied with AKT plus any user tools if loaded The list gives the name of the tool the names of the parameters the category to which it belongs and a description of its function me AKT s Tool Information Alphabetical List of Tools Supplied With AKT abonOnCondition Condition Message Test Output a message and abort current tool if Condition is true eg If user wants to stop execution when Statement number reaches 100 then abonOnCondition Statement numberz10D Completed 100 statements will abort execution when Statement numberz10 0 and output the message Completed 100 statements ask Question Answer Display Produce a dialog displaying a Question Whatever is typed in the dialog box by the user is returned in Answer ask yesno PromptResponse Test Prompt the user with a question The user has a choice of selecting either a es or No button If Yes is selected then tool will succeed with Response Yes If No is selected then tool will succeed with Response No calculate Function Result Miscellaneous
248. rt numbered Kb ListFormalStatements TranslatedStatements show Item show Item The variable tem in the first show Item primitive would be a message This message must be in inverted commas This is a numbered natural language version of the statements would be an appropriate message The variable tem in the second show Item primitive should be the statements themselves Thus ltem should be replaced by the output parameter of the third primitive TranslatedStatements Thus the final tool will look like this statements search Kb Term object all ListFormalStatements statements save Kb ListFormalStatements statements convert numbered Kb ListFormalStatements TranslatedStatements show This is a numbered natural language version of the statements show nl show TranslatedStatements You will note that show nl has been added to the fourth line in order for the statements to appear on a new line below the message rather than directly appended to it The new line is not necessary for the tool to work it simply makes the output easier to read Finally the tool is finished with a full stop and carriage return A tool can only be completed by putting a full stop at the end of the last line and entering a carriage return 1 Carry out Syntax Check on last time Your screen should look like Figure 10 15 below If the message Tool syntax is ok appears you can proceed to the next step Using Knowl
249. rtilizer sail sail extraction usage leaching erosion amount rate amount nutrient nutrient an increase in the rate of soil nutnernt leaching causes an Increase in the amount ot soil nutnernit leaching soil sol nutrient leaching availability amount nutrient an increase in the usage of tertiizer causes an increase in the fertility ot soll sail fertility crap production Figure 8 10 A diagram with some of the link labels switched off 8 2 5 HIDING NODES AND LINKS Sometimes it may be desirable to hide various nodes and links on a diagram to enhance its clarity or to remove nodes of only secondary interest The Hide Node Link button on the left hand side of the screen will hide links and nodes in a particular diagram without removing them from the knowledge base In order to hide a node and link you must hide the link first Therefore press on the Node Link button in the Hide box and then in the diagram window press the cursor down at one end of the link and release it at the other end of the link taking care to drag the cursor in the direction of the causal flow Once the link has been hidden you can then hide the node by pressing the Hide Node Link button once more and selecting the node H3 You can only hide a node if all the links that flow in or out of it have been hidden 8 2 6 REFRESHING A DIAGRAM Occasionally a diagram may become corrupted through other Window dialogs overla
250. s list box To view all the statements which form part of the topic hierarchy select Statements This will bring up a Search Results dialog box with all the statements in the topic hierarchy listed in natural language To delete a topic hierarchy highlight the relevant one and press Delete A message will appear confirming that the topic hierarchy has been deleted 7 12 3 APPENDING TOPICS TO A TOPIC HIERARCHY In order to append topics to a topic hierarchy highlight the chosen topic hierarchy in the Topic Hierarchies dialog box In the new dialog box Topic Hierarchy select Append An Append Topic dialog box will appear Figure 7 81 ee Append Topic treefodd kb j X KB Name treefodd EE gl incidi Appendto famers ppend to farmers AN Topic farmers crop attached to farmers Topic Ooo Eh m Topics farmers farmers_crop farmers_fodder scientists scientists_crop scientists_fodder tree_crop tree fodder Figure 7 82 Message confirming that the topic has been appended to the topic hierarchy Figure 7 81 Append Topic dialog box Select the chosen topic to be appended and press Append A message will appear confirming that the topic has been appended to the topic hierarchy Figure 7 82 In the example used here a topic hierarchy Farmers was created in the treefodd knowledge base to which the topics farmers crop and farmers fodder were appended The Topic Hierar
251. s pieces of generic code from which a tool can be constructed They are classified into a number of categories Cause and Effect Display Formal Term Hierarchies List Miscellaneous Sources Statement and Test These primitives can carry out searches on the knowledge base handle lists and manipulate the formal terms and statements A function is a generic term that could represent either a primitive system tool or a user defined tool Using Knowledge 119 Chapter Nine Reasoning with AKT tools 9 1 2 6 What is a control structure Control structures define special relationships between a set of functions thereby allowing different actions to be taken depending on the circumstances and allowing repetitive tasks to be specified efficiently Control structures allow primitives to be threaded together in if then else repeat until or foreach in do type of structures to create tools which can carry out more complex tasks that a single primitive might achieve 9 1 2 c What is a tool A tool is a collection of primitives together with control information defining the sequence in which they should be carried out They are classified as a Systems tools tools supplied with the AKT application that have been constructed using primitives and control structures to perform some generally useful function which is far too complex for a simple primitive b User tools tools created by you the user using the primitives syst
252. s Browse Tools 4 k Tool Body Note Must finish with a full stop then a new line __Print Tool Choose a topic fom all the loaded Ebs ignore Eb parameter knowledge base topics Topicsl list select Topics Please choose a topic Topic find all the topic s formal statements ignore Eb parameter topic statements Topic FormalStatements choose a search term Figure 10 9 700 details for the tool search Topic Statements The full tool body looks like this choose a topic fom all the loaded Kbs ignore Kb parameter knowledge base topics Topics list select Topics Please choose a topic Topic find all the topic s formal statements ignore Kb parameter topic statements Topic FormalStatements choose a search term ask Type in the terms you want to search for Can use connectives and or SearchTerm search the formal statements for selected term ignore Kb parameter statements search SearchTerm object FormalStatements TermStatements list all the numbered translations of the Formal statements foreach Statement in TermStatements do statements convert numbered Statement Translation show Translation show nl We will now go through the tool step by step As we go through the primitives that make up the tool look at each primitive in turn by using the Browse Tools button on the Tool Details dialog box Several things to note before we start a Ali
253. s a decrease in crude fibre content of tree a decrease in temperature of soil causes a decrease in vigour of crop a decrease in temperature of soil causes a decrease in rate of germination of crop en increase in rate of erosion of soil causes a decrease in fertility of soil an increase in rate of movement of soil causes an increase in rate of erosion of soi 630 the moisture content of shaded cropland soil is greater than open cropland soil i 4 k OK Cancel End search Topic Statements on 14 5 2001 at 16 54 32 Figure 10 7 The tool search Topic Statements in action continued Figure 10 8 The Tool output 1 These tools were created for the Atwima knowledge base Both the knowledge base and tool file can be downloaded from our website www safs bangor ac uk afforum Using Knowledge 131 Chapter Ten Creating your own tools Now we will look at the body of the tool If you return to the tool search_Topic_Statements and press Details the following dialog box appears Figure 10 9 Eg Tool Details search Topic Statements Tool user defined Current Tool GhanaTanals Description Tool will allow userto search for any term s in the chosen topic 1 Ask userto choose atopic e 4sk userfora search term Term can be a combination of terms connected by either and or or Paramete mut T outs Cd Tool Definition Tool Name Parameters oyntax Check search_Topic_Statement
254. s and pictures into the knowledge base HELP Chapter 12 answers the most common queries TUTORIAL Chapter 13 and 14 provides basic tutorials for using AKT chapter 13 gives you a quick guided tour around the knowledge base Atwima and chapter 14 is an exercise in building an example knowledge base APPENDICES AND REFERENCES These give you further information about knowledge base creation and references to other works on indigenous ecological knowledge KNOWLEDGE BASES Three knowledge bases are supplied with the manual soil treefodd and atwima Soil was created as a small example knowledge base treefodd and atwima are genuine knowledge bases the first capturing knowledge of farmers in the midhills of Nepal and the second capturing knowledge of farmers in the Atwima district of Ghana HOW TO INSTALL AKT5 R3 IMPORTANT AKT5 is designed for 32 bit systems only It will run on Win95 Win98 Windows NT4 and Windows 2000 Installing AKT5 from the CD ROM 1 2 3 Insert the AKT5 CD Rom into your CD ROM drive Double click on the file AKT5 Install exe Follow the instructions displayed on the screen If you wish to install AKT5 plus the User Manual the example Knowledge bases and a guide to the use of the knowledge bases then choose the Typical installation option If you just want to install the AKT5 application then choose the Compact option If you select the Custom option you can make your own c
255. s new KB in texturecolour kb File name Save as type Cancel Figure 7 75 Message to confirm that the topics have been saved as a new knowledge base Figure 7 74 Name of new KB dialog box Once you have entered a name for the new knowledge base and pressed Save the screen reverts to the original knowledge base and a message appears that the topics have been saved as a new knowledge base Figure 7 75 Knowledge Acquisition 86 Chapter Seven Software manual for AKT Ld Points to watch when converting a topic into a separate knowledge base When you convert a topic or group of topics into a new knowledge base the new knowledge base will contain all the sources and all the object hierarchies and topic hierarchies which appeared in the original knowledge base Only the formal terms that appear in the statements transferred to the new knowledge base and any object formal terms used by any of the hierarchies will appear in the Formal Terms list Before embarking upon expanding the new knowledge base it would be wise to check rigorously whether all the sources terms and hierarchies inherited from the original knowledge base are relevant to the new knowledge base Certain elements may need to be removed to avoid confusion and to uphold the principle of parsimony 7 12 TOPIC HIERARCHIES As one can have object hierarchies so one can create topic hierarchies A single knowledge base may contain a number of dis
256. s that might contain the superobjects or subobjects of the search term FormalStatements contains the output of Step 2 and TermStatements will contain any of these statetements that contain the search term s P liil Take five foreach Statement in TermStatements do statements convert numbered Statement Translation show Translation show nl This last step lists all the statements containing the specified formal term It translates them from the formal syntax into natural language and then displays them on the screen prefixed by the statement number For this final step the control structure foreach in do has been combined with two primitives one from the Statements category statements convert Mode Kb Original Converted and one from the Display category show Term Note if the do part of the control structure contains more than one primitive or tool then they need to be enclosed within parenthesis This sequence of instructions is a statements convert numbered Statement Translation The first input parameter Mode is set to numbered one of the mode options The second input parameter is the anonymous variable againand the third input parameter Statement Contains the formal statement to be translated and numbered b show Translation This primitive simply shows the numbered translation on the screen Show nl This last part simply instructs the tool to output a new line nl and carriage retur
257. sease the Boolean Search String should include brackets thus Tutorials 163 Chapter Fourteen Tutorial in creating a simple knowledge base burning and pests or burning and disease The searches which we have practised so far have retrieved only statements that contain the specified formal term However because we have additional information about object terms in the form of the hierarchies we can use alternative search strategies In the Search Options box it is possible to select 1 object 2 superobject 3 subobjects in any combination Now try out all the different search options one at a time The first option will give you only the statements containing the word crops The second option will give you all the statements containing crops or any of the subobjects rice beans or corn The third option will give you all the statements containing any of the objects in the object hierarchy plants K Creating Topics 7 11 1 You may wish to save a particular Boolean Search String to create a permanent subset of statements in your knowledge base These subsets of knowledge are called Topics and are created in the same way as any Boolean Search String the difference being that they are then saved as a topic Try creating a topic entitled management actions from a Boolean Search String containing the terms burning or clearing or harvesting
258. sh to add the formal term to the Kb as it does whenever you introduce a new formal term when you create a new statement Press Yes whereupon a message appears to confirm that the new term has been saved If you attempt to add a term which already exists in the knowledge base a message appears A term with the same name already exists in the kb Ri By pressing Save in the New Formal Term box you will only save the new term temporarily To save it permanently it is necessary to select Save KB or Save KB as under the main KB menu 7 7 3 DELETING FORMAL TERMS These added terms may also be deleted by highlighting them in the Formal Terms list and selecting Delete However it is not possible to delete a formal term that still appears in a formal statement In order to remove a formal term which appears in a formal statement the term must either be replaced using the edit function in the Statements menu see above 7 4 4 or by deleting the statement altogether using the Delete function in the Statements menu see above 7 4 5 7 8 SYNONYMS The synonyms option allows you to specify a synonym for a formal term An example of this might be the local name for a plant beside the common English name and the scientific Latin name For example the tree with the common English name shea butter tree has the scientific name Vitellaria paradoxa and is also commonly known in English by its French name karit whilst in the
259. soil erosion Thus despite having a clear understanding that larged leaved tree species were competitive with crops and promoted soil erosion farmers still planted them in association with crops The explanation for this was that farmers were trading off the negative impacts of these trees on crops and soil against their high fodder value at key times in the dry winter season Subsequent analysis of formally documented local knowledge Joshi 1998 indicates a positive relationship between leaf size and palatability of tree fodder among the species used by farmers gt 70 of trees classified by farmers as large leaved were also classified as having high palatability whereas 2096 of trees classified as small leaved were highly palatable This represents a key constraint in the system where farmers are having to sacrifice crop yield and tolerate soil erosion in order to obtain fodder at key times in the season Hence this identifies a leverage point where research to introduce or breed a smaller leaved tree with the same fodder characteristics as the large leaved species that farmers are currently using for example may represent an adoptable advance that addresses current constraints 1 7 3 THE UTILITY OF REASONING MECHANISMS The application of reasoning tools in knowledge base management makes the development of concise and coherent knowledge bases much less difficult and time consuming than it would otherwise be The application of rea
260. soning tools has also allowed novel approaches to knowledge analysis to be applied to complex sets of information These approaches would be untenably time consuming and complex to apply without automated reasoning Methodology 9 Chapter One Overview Finally trials have shown that reasoning tools are effective in allowing users access to the content of the knowledge base either to learn from it via tutorials or to use the knowledge in decision making The two main automated reasoning features supplied by AKT are 1 property inheritance 2 causal diagramming 1 7 3 a Property Inheritance In an object hierarchy that is organised in the form of an inverted tree with the root at the top and the branches below the lower objects inherit the properties or characteristics of the objects from which they are descended Take for example an object hierarchy describing plant taxonomy in which the name of the hierarchy or the SuperObject is plant whilst somewhere further down the tree one of the members sub objects descendants of the object hierarchy is lettuce Thus the statement watering plant causes plant growth to increase would mean that by property inheritance we could infer the statement watering lettuce causes lettuce growth to increase 1 7 3 b Causal Diagramming In some knowledge bases there may be hundreds of statements and it is difficult to determine the overall structure To enable the user to see what
261. station Press Yes The screen then reverts to the Diagram Interface and displays the two nodes connected by a link Figure 8 27 Although it is possible to select the Formal Terms button it is not possible to modify anything as the Statement Formal Terms box will be empty because the statement has as yet not been saved and the formal terms thus not yet entered into the knowledge base Knowledge Acquisition 115 Chapter Eight The diagram interface mg AKT current knowledge base New File KB Diagram Tools Help Diagram of the complete New knowledge base amp al cause C link Object Attribute Process Action EERE I a D Link m Delete Node Link E r Hide Node Link m Show Hide Label E opy to Clipbaa Memo Zoom In Zoom Out Centre Zoom lee Label Mode Undo Show Paths Print Window Navigate NN EEA L1 EN Rcs Statements m Causes Effects Causes Effects m Select Diagram 4 Figure8 27 A basic link and node diagram on the screen 8 9 EDITING DELETING A DIAGRAM STATEMENT In order to delete a statement represented by two nodes and a link you must delete the link first Select the Delete button from the diagram screen and then press the left hand button of the mouse down on the first node and release it on the second node RB RB In general there will be only one statement
262. t frequently because the issue in question is at the margins of his or her comprehension Intrinsic ambiguity often occurs in the meaning of terms within a statement Clearly distinguishing intrinsic ambiguity from the inability of the knowledge base developer to understand the concepts under consideration is a matter of judgement 5 3 EVALUATING SETS OF UNITARY STATEMENTS The content of a knowledge base is greater than the sum of the content of the individual unitary statements As a result iterative evaluation must include the consideration of sets of unitary statements as well as individual statements Sets of unitary statements should be evaluated in terms of e repetition e contradiction e completeness and e consistency in use of terms 5 3 1 REPETITION A compact knowledge base is significantly more tractable and therefore more useful than a less compact version Compaction is achieved by identifying and removing repetition in the knowledge base Two types of repetition can be identified strict repetition and deducible repetition Strict repetition is where a piece of information is stated more than once Deducible repetition is where a statement in the knowledge base can be deduced from other statements in the same knowledge base and is therefore superfluous Methodology 41 Chapter Five Knowledge base management 5 3 1 a Strict repetition AKT will not allow exactly the same statements from various sources to be added
263. t icide a d REMO ELMUerdnU LN EDS 5 9 la oUICEFeDOULORN c finer hte E vga oue edd eu oai caso I eere tee 5 3 1 6 Deducible repetition and the use of hierarchies in compacting the knowledge base eese 5 3 1 c The use of hierarchies in compacting the knowledge base 5 3 2 CONTRADICTION cirein tedio dea Ea uses OUR UstuevE TEES d ven dd RE Eus 5 9 9 COMPLETENESS sc utedet scree esses tae 5 3 4 CONSISTENCY AND PRECISION IN THE USE OF TERMG 5 4 EVALUATING HIERARCHICAL STRUCTURES essseeesrr 5 4 1 FORMAE TERM S oine a pvp soe uitasie rai temi tab Ova dor tt 0 4 2 RELATIONSHIPS BETWEEN OBJECTS eese 0 4 3 DEFINITION OF FORMAL TERMS esses CHAPTER SIX KNOWLEDGE BASE ANALYSIS sess 6 1 EVALUATION OF THE REPRESENTATIVENESS OF A KNOWLEDGE BASE 6 1 1 DEFINITIONS OF REPRESENTATIVENESS eese 6 1 2 VALIDITY OF ABS TRACTION aate noe abo rH Ste NR Uu E Esa xUEtPEEE 6 1 3 REPRESENTATION OF THE KNOWLEDGE HELD BY THE COMMUNI m Tr o 62 TWO METHODS OF TESTING REPRESENTATIVENESS eseeess CHAPTER SEVEN SOFTWARE MANUAL FOR AKT s Tok INTRODUC HON us denovstt ies n ate RS ea unn Eb eee a ra Peau ee data o oe L2 GETTING STARTED Xtra upon ten a arenae ic xU Ue eRU e E P MERE ES 7 3 STARTING WORK ON A KNOWLEDGE BAGE 0 0 ccc cece eee eeeee
264. t if the knowledge base developer is to make effective use of the knowledge base Comparison of the use of the same term in different statements ensures the consistency of meaning Comparison of apparently similar terms identifies overlaps in terminology Terminology in knowledge systems about agroforestry is rarely consistent or precise A demand for an exacting consistency when creating knowledge bases may lead to a proliferation of terms There is then a danger of increasingly unrepresentative use of those terms by source communities Here again the strategy to be taken depends on objectives in the creation of the knowledge base They may be primarily to study the current state of knowledge of a target community or to develop a knowledge base for use in providing decision support 5 4 EVALUATING HIERARCHICAL STRUCTURES As well as evaluating and modifying unitary statements iterative evaluation of the knowledge base demands evaluation of the formal terms specified the relationships between those formal terms and their definitions 5 4 1 FORMAL TERMS Identifying and removing repetitious terminology can significantly increase the utility of the knowledge base The lists of formal terms available in AKT encourage consistent use of terminology particularly through formal representation Nevertheless regular comparison of the various formal terms may reveal overlapping terminology The ability to identify equivalent terms for the same object i
265. t individuals for different knowledge bases these decisions will not have been consistently applied to both sets of knowledge The implications of inconsistency in formal representation for automated reasoning are likely to be serious Thus although it is possible to create a large knowledge base by merging two or more smaller knowledge bases it is much simpler and much more feasible to begin with a large knowledge base and then split it into smaller ones Key points of Chapter Four Unitary statements are the basic units of statements in a knowledge base Contextual information can be stored with knowledge statements The definitive clause grammar has been tailor made for representing knowledge in statements that can be processed by the computer Six elements form the basis for representing knowledge object process action attribute link and value Formal statements can be one of the following attribute value statement negative attribute value statement causal statement link statement comparison statement Methodology 34 Chapter Four Knowledge representation Determining the elements formal terms specification the structure of the statement and statement type are important steps in formalising a knowledge statement Knowledge statements can be entered using the diagram interface through nodes and links Knowledge bases can be split and combined as and when necessary Methodology 35 Chapter Five
266. tails will appear automatically The screen below Figure 7 29 is the Object Hierarchy dialog box for the object hierarchy Livestock in the treefodd knowledge base The left hand side of the dialog box shows the Objects in Hierarchy list which is simply an alphabetical list of all the objects in the hierarchy The central panel headed Hierarchy Structure gives the structure of the hierarchy immediately above and below the selected object with the selected object highlighted in the middle box under Object and also in the Selected Object box at the top under the hierarchy name In Figure 7 29 the object in the Selected Object box is Livestock As that is also the hierarchy name there are no objects listed in the SuperObjects box In the Immediate SubObjects box are listed animal and bird If we highlight another object in the Objects in Hierarchy list for example large_animal the objects in the Hierarchy Structure section will automatically change to Figure 7 30 Now animal appears as the superobject and buffalo and cattle as the immediate subobjects Knowledge Acquisition 65 Chapter Seven Software manual for AKT ee Object Hierarchy treefodd kb KB Mame treefodd Recaro Selected Object Livestock Objects in Hierarchy Hierarchy Structure Super bjects nane Close Object Details Selected object Append to Ww
267. tation When unsustainable slash and burn is practised by newcomers however the soil is sometimes left uncovered This can lead to major erosion problems particularly in hilly areas Tutorials 155 Chapter Fourteen Tutorial in creating a simple knowledge base When the soil is bare and erosion a problem the siltation rate of the waterways is increased and this often has a negative effect upon aquatic life forms and fish production Neither are weeds a difficulty in the traditional method because the land is left to fallow as soon as they become a problem In the subsequent fallow period weeds soon die out as the crown of the secondary forest closes Migrant farmers however will remove all vegetation and the roots and stumps of the felled trees from the areas they clear for intensive farming These practices mean that when the land is finally abandoned there are no rootstocks left from which the trees may grow and grasses are the most common invaders of the open areas This means that clearing of land by migrant farmers generally results in the permanent destruction of the rain forest he intention behind creating a knowledge base in AKT is to represent knowledge that provides a description of the ecology of a particular agroforestry practice This is achieved by abstracting a set of unitary statements from the source knowledge that as a set represent a coherent description of the ecology of the practice This process of bre
268. tement cannot be entered without a source see above 7 4 2 However only one source per statement can be entered via the Statements menu see above 7 4 1 whereas there may be several sources for one statement Additional sources can therefore be entered via Sources in the main KB menu Knowledge Acquisition 72 Chapter Seven Software manual for AKT The Information Source dialog box is exactly the same as that entered via the Statements dialog see 7 4 2 Figure 7 48 below is the Information Source dialog box of the knowledge base treefodd me Information Source Please select information source Selected Source L Joshi 19954 Type Interview amp reference 7 Sources Mew L Joshi 1985a Livestock Scientists 1994 Plant Scientists 19944 Salma Farmers 1994 Salma farmers 1995a Reference _oK Interview Figure 7 48 The Information Source dialog box entered directly via Sources in the main KB menu The details of existing sources can be accessed via Details New sources can be entered by highlighting the relevant radio button and pressing New The two dialog boxes Create a new interview source and Create a new reference source function in exactly the same way as described in 7 4 2 Sources can be deleted by selecting Delete However sources which are attached to statements can only be deleted if there is more than one source for that particularly statement ms
269. tements are syntactically identical but they are significantly different in utility Explanatory ecological knowledge can be derived from statements of instance however statements of instance are in themselves data and are unlikely to constitute a useful component of a knowledge base 4 1 3 RECORDING THE CONTEXT OF A STATEMENT Knowledge is inescapably contextual Disaggregation of knowledge into a set of unitary statements will cause this context to be lost This loss of contextual understanding demands explicit information about the circumstances under which the statements apply i e conditions and the source of each statement 4 1 3 a Conditions Most unitary statements will have only a limited validity Validity relates to the circumstances or conditions under which the unitary statement is held to be true and the certainty that can be placed on the unitary statement being true Neither are adequately captured in unitary statements themselves Appending conditional information and certainty to a statement results in a more complete record of the knowledge articulated by an informant However it is extremely difficult to elicit meaningful information about the confidence informants have in the knowledge that they articulate Furthermore use of statements of certainty is problematic For this reason AKT provides facilities for recording conditions e g Soil erosion is severe IF the slope is greater than 20 AND rainfall is over 1000 m
270. tent of the Knowledge base in order to help you in its exploration Or you may wish to save your statements to another package and print them out from there Try printing out all the statements in your Topic management actions Select the main KB menu Select Topics Select management actions Press Search Print the Print Statements button at the bottom of the Search Results dialog box Try printing the statements directly and try saving them as a text file as well OO ex NS X USING TOOLS 9 and 10 As this is a tutorial for beginners and the knowledge base slash and burn is only very small you would not normally need the tools at this stage However just to give you a little taster of what tools can do here are two for you to try out The following is a little exercise to introduce you to some of the tools and what they do To get started select the main Tools menu and then press Tools Systems Tools and finally Knowledge Evaluation 1 The tool kb report Kb gives you a summary of the categories of statements in your knowledge base Press Run A dialog box appears requesting the name of the knowledge base Enter the name of your knowledge base and press Continue The tool output will give you the following output Total number of statements 22 of which 5 are conditional Number of attribute statements 5 of which 5 are conditional Number of causal statements 14 of which 0 are conditional Number of c
271. terpreter Data is a recorded set of observations which may be quantitative or qualitative and information is a continuum that has data and knowledge as two extremes Figure 1 1 Information data and knowledge are distinct from understanding Understanding is the outcome specific to the interpreter of the interpretation of information data or knowledge INFORMATION understanding knowledge human mind Figure 1 1 Diagrammatic representation of Information as a continuum with Data and Knowledge as the two extremes Knowledge is seen as a central aspect of culture derived from education and experience that may be used in conjunction with a certain value system and competing priorities and possibilities to make decisions Local knowledge and indigenous knowledge have often been used interchangeably However it is possible to distinguish between the two if local knowledge is used to denote locally derived understanding which is based on experience and observation and indigenous knowledge is used to denote that same understanding but modified by the incorporation of cultural beliefs and values as well 1 8 KNOWLEDGE BASE CREATION Creating a knowledge base involves four distinct stages knowledge elicitation from the appropriate sources converting the knowledge elicited into simple unambiguous statements inputting those statements into AKT using formal representation and specifying defining the formal terms used Knowl
272. the following forms Attribute statement causes attribute e g A decrease in stem thickness causes a decrease statement in stem strength Process causes attribute statement e g Soil erosion causes a decrease in soil fertility Action causes attribute statement e g Ploughing slopes causes an increase in soil erosion Object causes attribute statement e g Cows cause an increase in soil compaction Causal statements can be divided into those for which the reciprocal is also true and those for which it is not For example both the statements a An increase in atmospheric temperature causes an increase in germination rate and b A decrease in atmospheric temperature causes an decrease in germination rate might be held to be true As they are reciprocals of one another it is desirable to be able to enter just the one into the knowledge base and be able to infer the other However the reciprocal is not always true For example while it may be true that An increase in intensity of rainfall causes an increase in surface moisture it is not the case that A decrease in intensity of rainfall causes a decrease in surface moisture because it is not rainfall but evaporation drainage etc which dictate the rate of drying To capture this difference two versions of causes are supported causesiway and causes2way For these six examples these result in the formal statements An action should usually be attached to at least one o
273. the page to reposition it Figure 8 13 below is the same diagram as Figure 8 12 above but demonstrates how a diagram might be rearranged Knowledge Acquisition 102 Chapter Eight The diagram interface ms WINAKT current knowledge base soil File KB Diagram Tools Help 101 Title Diagram 101 Memo r Add node Object Attribute Process Action Link d RE Node Link r Causes Effects Node Link i f T Causes Effects r Select Diagram Es es w gt a M ES a m Label Figure 8 13 Rearranged diagram of the pathway between field steepness and crop production rearranged to fit onto the screen at full scale It is possible to highlight more than two nodes before selecting Show Paths However the more nodes highlighted the more complicated the subsequent pathways in the sub diagram become 8 3 2 NAVIGATING If a subsection of the main diagram is required for further investigation it is possible to build one up level by level to incorporate those nodes of particular interest by using the Navigate button When you select Navigate and click it over a chosen node all the immediate causes and effects of a particular node appear As an example take the livestock element in the soil knowledge base 1 In the main diagram highlight two adjacent nodes related to livestock in this case animal fodder amount
274. the statement has been deleted If you wish the statement to be permanently deleted from the knowledge base you must save the knowledge base after deleting the statement S WARNING Any formal terms associated with the statement will be deleted unless they are also used in other statements 7 4 5 DIAGRAMMATIC REPRESENTATION At the bottom of the Statement card are various options for diagrammatic representation Figure 7 26 b4 irrigation of khet causes an increase in availability of sail nutrient 65 a decrease in frequency af rainfall causes a decrease in amount of rainfall bb an increase in rate af sail nutrient leaching causes an increase in amount of si b a decrease in amount of application of compost in field causes a decrease il Be an increase in rate of soil erosion causes an increase in amount of soil erasiar Y Diagram Selection Type Al Statement Causes Effects Navigate rint Statements Figure 7 26 The diagram options at the bottom of the Statements card If you select All Statements it will give you a diagram of all the causal and link statements in the knowledge base If you highlight a statement and press Causes it will give you a diagram showing all the connections i e causes flowing into the selected statement If you highlight a statement and press Effects it will give you a diagram showing all connections i e effects flowing out of the selected statement If there are no causes or no eff
275. the tools Highlight the primitive you think you need and then select Details The Description within the Tool Details will enable you to decide whether or not it is indeed the primitive you want to use Once you have the desired primitive highlight the Tool Name Parameters box and press Ctrl c to copy it Return to the New Tool dialog box and taking the cursor to the tool body box press Ctrl v to paste it into the tool Method 2 Another method of copying a primitive once you are familiar with the program is to select Help from the main menu and from the dropdown menu that appears select Tool List The following screen will then appear Figure 10 12 Eg AKT s Tool Information Alphabetical List of Tools Supplied sth AKT aborOnCondition Condition Message Test Output a message and abort current tool if Condition is true eq If user wants to stop execution when Statement number reaches 100 then abart nConditiani Statement_number 100 Completed 100 statements will abort execution when Statement_number 100 and output the message Completed 100 statements ask QuestionAnswer Display Produce a dialog displaying a Questian Whatever is typed inthe dialog box by the user Is returned in Answer ask_yesno PromptResponse Test Frompt the user with a question The user has a choice of selecting either a res or No button lf Yes is selected then tool will succeed with Response Yes If Na
276. this tool you will see that there is an anonymous variable where the Kb parameter would normally be This means that the knowledge base parameter will match any loaded Kb name i e the tool will search all the loaded knowledge bases rather than a specific knowledge base list select Topics Please choose a topic Topic This primitive is from the List category and its generic form is list Operation List Item Result The variable Operation is replaced by the term select In the Description box of the primitive is a list of all the possible terms that can be used for the variable Operation select is one of the possibilities The variable List is replaced by the variable Topics which will gives a list of all the topics found by the previous primitive The variable Item is specified as the message Please choose a topic which has to be enclosed in inverted commas Finally the variable Topic will contain the name of the topic selected by the user H3 Remember parameters which start with a capital letter are variables unless they are enclosed in inverted commas whereas parameters which start with a small letter are atomic terms and do not change qu llli Take two topic statements Topic FormalStatements This step will find all the formal statements about the topic selected in step one The primitive is from the Statements category and its generic form is topic
277. tion Timing of Knowledge Collection September 1995 to July 1996 This knowledge base was developed by st mn Acknowledgements The development of this knowledge base was Funded by the UK Department of Intermatienal Development General This knowledge base was created as part of the Comments doctoral thesis Joshi Laxman 1997 Incorporating Farner Figure 7 60a The Memo dialog box Figure 7 60b The Further Details dialog box Each section of the memo dialog box Figure 7 60a is self explanatory e Title of this knowledge base Here the full title of the knowledge base should appear for example the full title of the treefodd Knowledge base is Tree Fodder and Indigenous Knowledge in Nepal e What the knowledge base is about Here the area of local knowledge covered by the elicitation process should be described e This knowledge base was developed by Here the name of the knowledge base developer s is are recorded e Acknowledgements here all acknowledgements are listed to those other than the developers who assisted in the design and creation of the knowledge base and to any funding bodies that supported the project If you press on Further Details another dialog box appears Figure 7 60b giving further details of the knowledge base e Purpose If the knowledge base was built as part of a particular project or designed to supplement work in a certain fiel
278. tional to leaf area index of that plant is a unitary statement By contrast Rainfall is low is not a unitary statement because it does not contain enough information to be used in reasoning it does not refer to any system any time or any place Clover is eaten by sheep and goats is not a unitary statement by this definition because it can be broken down into two unitary statements 1 Clover is eaten by sheep 2 Clover is eaten by goats Unitary statements are divided into two categories binary statements and attribute value statements Methodology 19 Chapter Four Knowledge representation A binary statement captures a relationship between two entities e g Rainfall causes increased soil erosion Attribute value statements describe an attribute of an entity or classes of entities e g Bananas are yellow This distinction is important in the diagrammatic representation of knowledge Within AKT binary statements can be represented diagrammatically but attribute value statements cannot Unitary statements can also be divided into those which refer to classes or types of entities termed statements of class and those which refer to particular instances termed statements of instance Statement of class Barley seeds germinate in seven days at 10 C statement of instance Seedling 97 germinated after nine days at 10 C These two forms of sta
279. tions of and requirements for representativeness depend on the objectives for the creation and use of a knowledge base A knowledge base may be evaluated in terms of for example e the extent to which the knowledge in the knowledge base represents a valid abstraction of the knowledge of the sources from which it was elicited or e the extent to which the knowledge elicited from a sample of a community and represented in a knowledge base is representative of the knowledge held by all that community 6 1 2 VALIDITY OF ABSTRACTION An objective measure may be required of the extent to which the knowledge base represents a valid abstraction of the knowledge held by the sources Such a measure may be needed if for example the knowledge base is to be used in planning extension activities targeted at the group of informants 6 1 3 REPRESENTATION OF THE KNOWLEDGE HELD BY THE COMMUNITY Knowledge bases may be required which represent the Knowledge of a defined community Usually these will be created through knowledge elicitation from a sample of the community s members Consequently further knowledge elicitation is needed to ensure that the knowledge base is also representative of the broader community The content of the knowledge base will be compared with knowledge held by members of the community not interviewed initially The extent to which a knowledge base that is assumed or has been shown to be a valid abstraction of the knowledge o
280. tive analysis of scientists and farmers knowledge about the tannin content of tree fodder and its implications for feeding farm animals The existence of formally documented records of farmers and researchers knowledge about the nutritive value of tree fodder Thapa 1994 Thapa et al 1997 made it possible to compare the equivalence of terms used by farmers and scientists This was done using automated reasoning Kendon et al 1995 and it was found that there was some equivalence between the way in which farmers used the term leaf bitterness and scientists used the term tannin content put simply fodder that scientists described as having a high tannin content tended to be described by farmers as bitter However while scientists had some detailed knowledge about the role of tannins in protein digestion by ruminants and decomposition of leaf litter they knew very little about the actual tannin contents of the 90 native species used by farmers and how this varied seasonally In contrast farmers did not possess detailed knowledge about the mechanism of action of tannins in ruminant digestion although they did associate leaf bitterness with low palatability and nutritive value Thapa et al 1997 and their local classification of fodder appears to encompass implicitly effects of tannins on protein supply to the duodenum in cattle Thorne et al 1997 Farmers could however articulate detailed knowledge about how leaf bitt
281. to the following procedures I All the diagrams and pictures that are to be incorporated into the knowledge base must be in the form of bitmap files ii All these bitmap files must be in the same folder as the knowledge base iii The thumbnail picture or diagram to go on the Welcome Page must have exactly the same name as the knowledge base in the above example atwima bmp for the knowledge base atwima kb iv All the other pictures and diagrams must contain the name of the knowledge base somewhere within the file name e g indigenous people atwima bmp settler people atwima bmp v These file names will then automaticaly appear when you select Pictures Diagrams in the second part of the Welcome Page The diagrams in this chapter are taken from Obiri Darko B Ayisi Jatango J Anglaaere L Cobbina J Moss C McDonald M Sinclair F and Young Einir 2000 Livelihood systems and farmers ecological knowledge in Ghana a report on three districts Shortened Bush fallow Rotations for Sustainable Livelinoods in Ghana DFID Project R7446 School of Agricultural and Forest Sciences University of Wales Bangor U K Using knowledge 146 Chapter Twelve The help facility CHAPTER TWELVE THE HELP FACILITY The Help menu Figure 12 1 offers you the following facilities A summary of the AKT formal grammar A list of all the tools available to AKT including any tools in the current User Tool file A list of the publicati
282. tool and then we will analyse how it has been built up To run the tool press Run Figure 10 5 A dialog box appears requesting you to select a topic Figure 10 6 Select your topic in this case scientists and press OK Eg User defined tools in file Ghanalools EJ ge Selectfrom 9 items Tool search_Topic_Statements FIBRE SII Categor L Josh l farmers Tools Tool Options farmers_crop choose_Any_Term Term ENT farmers fadder chaase Kb Term Kb Ter scientists examine All Topics scientists crop examine Common Topics Details scientists fodder search For Any Terms tree fodder Far KB Rew tree crop search Topic Stateme nts Delete 4 search Topic Statements OK Cancel No ot Tools 8 Figure 10 5 User defined tools Figure 10 6 The too search_Topic_Statements in action A new dialog appears requesting you to type in the formal term terms that you want to search for in this case soil Figure 10 7 Press OK The tool output Figure 10 8 will then give you all statements containing the term soil in natural language from the topic scientists gg Tool output search_Topic_Statements 0 ge Query tool Selected treefodd Type in the terms you wantto search for Can Output use connectives and or Results of running the tool Call search_Topic_Statements 0 on 14 5 2001 at 15 54 20 shading causes a decrease in temperature of soil an increase in dampness of soil cause
283. tratified random sample from the source community is appropriate The purpose of stratifying the selection of informants is to ensure coverage of knowledge about the domain where different classes of people may have different knowledge Key determinants of variability in knowledge relative to research objectives may be gender education occupation location religion ethnic group etc Appropriate strata combining these Methodology 12 Chapter Two Knowledge Elicitation factors to allow assessment of the influence of these factors on the distribution of knowledge are identified Within each stratum informants are then purposely selected A similar approach can be applied to professional communities by discipline for example However the relatively small size of professional communities or bibliographies mean that in practice the distinctions between definition and compilation may be blurred 2 1 1 d Generalisation Having obtained a knowledge base from a few informants the generalisation stage involves testing the representativeness of this knowledge across the community as a whole This requires a random sample that is statistically representative of the community as a whole typically upwards of 100 people who have not been previously interviewed This phase has one or more of the following objectives e To validate the knowledge base as representative of the knowledge held by the community as a precursor to using it to inform researc
284. two types conflicting and inconsistent Conflicting knowledge is knowledge from two different sources which is contradictory Inconsistent knowledge is knowledge from a single source which is contradictory X Until contradiction is resolved either by rejecting one unitary statement in favour of another or by demonstrating that apparent contradiction does not represent actual contradiction the two contradictory unitary statements can be viewed as being competitive Where contradictory knowledge in the knowledge base is identified it may be resolved through further knowledge elicitation or flagged within the knowledge base Contradictory unitary statements may become apparent at any stage during the creation of the knowledge base Equally contradictions may only become apparent once the implications of the knowledge have been illuminated through reasoning with that knowledge Once contradiction has been identified it may be resolved by one of two means e Apparent contradiction may be resolved through clarification of the meaning of contradictory statements in particular two apparently contradictory statements may be distinguished by specification of the conditions under which they are held to be true e Contradictions may be resolved by demonstrating that there is a significant difference between the reliability of two statements such that the less reliable statement can safely be rejected in favour of the more reliable However it is importa
285. u have selected the knowledge base file and pressed Open you will return to the AKT main menu with the name of the knowledge base in brackets next to the AKT heading in the top left hand corner of the screen Simultaneously a memo dialog box appears on the screen designed to give the new user a brief introduction into the knowledge base they have selected see 7 9 below for a full description on the Memo dialog box Once you have read the information press Close to continue Knowledge Acquisition o3 Chapter Seven Software manual for AKT 7 4 ENTERING KNOWLEDGE THROUGH THE STATEMENT INTERFACE Formal statements are entered through the Statements interface in the KB menu see Figure 7 3 If you are starting a new knowledge base the Statements dialog box will be empty as in Figure 7 5 below If you are adding statements to an already existing knowledge base the statements previously entered will be listed in the All Statements box as in Figure 7 6 showing the Statements dialog box in soil kb me Statements new knowledge base ms Statements soil knowledge base Number of Statements O Details Number of Statements 73 Details r Selected Statement m Selected Statement Natural Language E dit Natural Language Edit gt New 4 New Formal Language Formal Language Delete Delete 4 gt Close iss P 1 Sort by Category Sort by Category none t
286. uilding up the knowledge base Control structure Program segments within AKT which control when and upon what knowledge the primitives are used Data A set of observations may be quantitative or qualitative Domain Subject or topic area under consideration Ecological knowledge Knowledge about organisms interactions amongst organisms and between them and their environment Explanatory knowledge Knowledge providing an explanation of phenomena Emic Internally generated explanation of phenomena i e from within the affected community Etic Externally generated explanation of phenomena i e from outside the affected community Expert The local farmer recognised as an authority in a particular aspect of the local farming system Formal Term The key components that make up the unitary statements in the formal language All words entered into the unitary statements that do not belong to the formal grammar are formal terms Generic Describes something applicable or referring to a whole class or group Hierarchy Classification of objects whereby all objects under a higher level object share all its attributes Indigenous Knowledge Local knowledge which has been modified by the incorporation of cultural religious beliefs and values Informant The interviewee from the local community who has supplied a particular piece of knowledge Inheritance Objects in a classificatory hierarchy sharing properties of higher level
287. urning helps to control pests and diseases the higher soil temperatures that follow clearing and burning also accelerate the decomposition of organic matter in the top layers of the soil About half of the nitrogen and phosphorus in the burnt material and nearly all the remaining nutrients are released to the soil from the ash after burning These nutrients are flushed from the ash by the rain and have the effect of raising the pH of the upper layers of soil as well as incorporating the nutrients Nutrients in concentrated form are thus available for one or two years after clearing The quantity and quality of these nutrients depends on the native fertility of the soil Crops such as corn rice beans cassava yams and plantains are then planted As nutrients are removed by crop harvests or lost through leaching soil fertility declines At the same time the relatively easily removed broad leaved weeds are replaced by harder to manage grasses and increasing weed density quickly impedes further cropping The fields are then abandoned for a period of fallow The secondary forest grows rapidly during the fallow using nutrients remaining in the soil Essential minerals phosphorus potassium calcium etc are extracted from lower soil layers during regrowth and brought to the surface by trees Soil erosion is seldom a problem in shifting cultivation because the cleared areas are small and are always covered by some sort of vege
288. uses an increase in amount of animal fadder Kdost COnne 46 an increase in availability of private_fodder causes an increase in amount of animal_fodder node 47 gt an increase in amount of animal fodder causes an increase in number of animal 43 a decrease in availability of farm labour causes a decrease in number of animal 5D a decrease in number of animal causes a decrease in availability of animal manure Details 51 a decrease in availability of animal manure causes a decrease in fertility of soil 52 a decrease in amount of animal_fodder causes a decrease in amount of crop residue bl a decrease in availability of sail nutrient causes a decrease in fertility of soil b a decrease in amount of application af campaost in field causes a decrease in fertili of soil Delete Find Print Close CHEREE Figure 8 19 The statements that are incorporated into the diagram in Figure 8 16d 8 5 MOVING BETWEEN DIAGRAMS In order to move between diagrams there are two arrows lt and gt in the Select Diag box in the bottom right hand corner of the screen which allow you to move backwards and forwards between diagrams The diagrams are numbered chronologically If a sub diagram is deleted that diagram number is deleted as well DIAGRAM SIZE It is worth bearing in mind diagrams with more than 40 statements have limited use as a means of trying to illustrate the interconnectivity of the statements 8 6 SAVING DIAG
289. ve them Therefore it is necessary to select Save KB from the KB menu before closing lt is good practice to save every few minutes to avoid losing work due to power failures etc 1 There are two distinct sets of interfaces in AKT for entering viewing and editing knowledge These are the KB for Knowledge Base Figure 7 3 and the Diagram interfaces Chapter 8 We will begin with the KB interface Knowledge Acquisition 52 Chapter Seven Software manual for AKT 7 3 STARTING WORK ON A KNOWLEDGE BASE When opening the AKT program you will either want to work on a new knowledge base or continue working on an existing one 7 3 1 STARTING ON A NEW KNOWLEDGE BASE oelect New KB from the KB menu You must select the directory in which you wish it to be stored and give the knowledge base file a name Ri Your knowledge base will be saved in the same folder as AKT unless you specify otherwise lt is recommended that you set up a separate folder for knowledge bases Type the name and press Save You will then return to the main menu as in figure 7 2 only now the name of the new knowledge base will appear in the top left hand corner of the screen in this case trees Figure 7 4 ge AKT current knowledge base trees File KB Diagram Tools Help Figure 7 4 Opening menu of a newly named knowledge base 7 3 2 OPENING AN EXISTING KNOWLEDGE BASE If you are opening an existing knowledge base select Open KB Once yo
290. vent it is clearer to refer to death of an organism as an event rather than a process but an event is simply a special type of process that occurs instantaneously From the point of view of the semantics of a diagram they are equivalent Action nodes refer to management actions An action is a type of process and actions could be represented as processes however an action is distinct in that there is a human directly responsible for causing the process to occur Attribute nodes refer to a particular attribute of a process or an object An attribute is something relating to an object or process that might be measured e g height of oak tree rate of germination colour of flower Experience shows that attribute nodes are more frequently used than object action or process nodes 4 4 2 6 Labelling of nodes Node names that contain implicit meaning are ambiguous For example nodes in influence diagrams might be given the name of objects e g pests or processes e g grain set while the links mean influence s However pest influence grain set is incomplete information all that it explicitly states is that some attribute of pests influences some attribute of grain set Where this attribute is known it has to be stated rather than implied e g pest population size influences timing of grain set if Knowledge is to be explicitly stated Complete information about the meaning of each node is critical for explicit
291. w dialog box appears announcing Statement saved If you press No then the statement will not be saved and you will be returned to the New Statement dialog box S WARNING Save in the New Statement dialog box only saves the statement in memory temporarily To save it in the knowledge base permanently you must select Save under the KB menu 7 4 3 EDITING A STATEMENT Once a new statement has been saved the programme automatically reverts back to the updated Statements dialog box Figure 7 15 from which all existing statements can be accessed For large knowledge bases accessing particular statements may be facilitated by doing a Boolean Search restricting the statements to a set containing the formal terms of interest see section 7 9 below Knowledge Acquisition 58 Chapter Seven Software manual for AKT eo Statements soil knowledge base Number of Statements 3 Selected Statement Natural Language E dit AF cultivation of sandy soil causes an increase in production of crap if the amount af c Mew Delete anincrease in scale of migration of Farmer causes a decrease in pressure on forest of population adecrease in pressure on Forest of population causes a decrease in intensity of Forest degradatior a decrease in intensity of forest degradation causes an increase in availability of forest_fodder Doan increase in availability of forest_fodder causes an increase in amount of animal fodder Doa
292. wledge base 7 10 1 THE BOOLEAN SEARCH The Boolean Search offers a search criterium for creating subsets of knowledge You can search for individual keywords formal terms or sources It is also possible to link any of these together using and and or or or even whole hierarchies or subsets of hierarchies and then search for these It is also possible to carry out a search combining formal terms with sources Ri For demonstrating the functions available in the Boolean Search we have used the knowledge base soil A Boolean search is carried out by selecting Boolean Search under the main KB A Boolean search dialog box appears Figure 7 61 we Boolean search soil Display Kb terms of type Name of new topic List of existing terms in Kb Save search selection Save r of the specified type Farmers 19978 Gurung 1997a access amount Details Close animal animal fodder Boolean options r Search options C subobjects AND OR superobjects Number of terms 91 pee Clear r Boolean Search String 1 b Figure 7 61 The Boolean Search dialog box Knowledge Acquisition 79 Chapter Seven Software manual for AKT The Display KB terms of type box will give you the option of selecting one of the seven formal term types as well as sources synonyms and topics Highlight the type required The List of existing terms in K
293. x Figure 7 8a or the reference dialog box Figure 7 8b will appear To create a new interview source the informants name the date of the interview and the informant s gender is recorded If the sample of farmers interviewed is to be stratified in any way other than by location and gender it is possible to introduce other criteria into the USER defined fields In the User identifier 1 box you put the type of stratification for example religion or caste or wealth ranking etc In the box beside it you put the group to which informant belongs e g Muslim or Brahmin or wealth rank A To create a new reference source the name s of the author s date of publication title and other information are recorded Eg Create a new interview source eg Create a new reference source SOURCE Save SOURCE Name oo Name Location derma Yen E Year 2001 fear Suffix a Gender USER defined fields Jerdi id unen qos seed Userideniier2 o o oo y Pubishe DATE City Po O Delat Source Day Month Figure 7 8a The interview dialog box Figure 7 8b The reference dialog box The year suffix is to enable you to distinguish between multiple interviews or multiple articles by the same person within the same year If it is felt that more detail is needed either about the informant for example age family background ethnic group or about the reference then this information can
294. xible and may be adapted for application in a range of contexts Furthermore the AKT software can be customised to meet particular needs Some approaches to customisation for example the creation of customised reasoning tools are outlined in the manual This publication documents the methodology as it stands at the end of the third major cycle of development in July 2001 For details of subsequent development or if you are interested in adapting the methodology for implementation at an institutional level please contact Dr Fergus Sinclair school of Agricultural and Forest Sciences University of Wales Bangor Gwynedd LL57 2UW UK Email akts bangor ac uk HOW TO USE THIS MANUAL INSTALLATION These are the instructions for installing the AKT program on to your computer METHODOLOGY The first six chapters of this manual outline the methodology for knowledge base creation and use It is important that you read these before beginning to construct knowledge bases for practical use KNOWLEDGE ACQUISITION Chapters 7 and 8 demonstrate how to install AKT and give detailed guidelines on how to use it to create your own knowledge base using both the statement and the diagram interfaces USING KNOWLEDGE Chapters 9 and 10 introduce the reasoning tools and explain how to create your own reasoning tools for exploring and evaluating the knowledge base INCORPORATING PICTURES AND DIAGRAMS Chapter 11 describes how to incorporate diagram
295. y attaching the information about changes occurring to the link rather than the nodes So increase in leaf area causes increase in crop yield becomes Methodology 31 Chapter Four Knowledge representation leaf area increase in Causes increase in crop yield see Figure 4 1 Over a large diagram the discipline of attaching the majority of information to the link simplifies diagram construction a causes Increase Increase in leaf in crop area yield causes Increase Decrease in pest in leaf attack area b increase decrease pest attack crop yield causes decrease causes decrease Figure 4 1 Two ways of expressing the same thing a shows the information attached to the nodes whilst b shows the bulk of the information attached to the links and the advantages in reducing the number of nodes that ensues 4 4 3 6 Stating the meaning of links If a diagram is to represent an explicit statement of knowledge links can only remain unlabelled if they all have exactly the same meaning and this meaning is clearly defined This makes the mixing of different types of link in a single diagram impossible and is extremely restrictive where the links are considered to be the primary source of information The explicit statement of the meaning of each link facilitates the flexible development of a representative diagram 4 4 3 c Linguistic c
296. y fertilizer emp price EHE an increaze in the amount of i f mantal eases 3n increase in th an increase in the intenzit a decrease in the price of an increase in the rate of Soil sl m4zjan Chop cultivation causes antertiliser causes an increase in erosion causes an increase in the ie In the amount ot soll nutmithe usage ot fertilizer amount ot zoll erosion zaching extraction sail fertilizer sail sail extraction usage leaching erosion amount rate amount nutrient nutrient an increase in the amount of soil an increase in the rate of soil nutnent extraction causes an nutnernt leaching causes an decrease im the availability ot Increase in the amount at soil zai nutnent nutnernit leaching sail sail nutrient leaching availability amount an increase in the amount af soil nutrient rartriant losaching causes an an decrease in the availability the awalabity of f at Soll nutrient causes a decrease uses ani increase In in the fertility of ol ue remt of zoll Sail fertility a decrease in the fertility of an increase in the amount i Soll causes a decrease in the erosion causes a decrease production ot crop production ot crop crop production Figure 8 9 Diagram giving the full natural language statement As in Figure 8 7a where symbols overlapped here in Figure 8 9 statements overlap To reveal the statements hidden behind other statements select the superimposed statement with the left hand mouse button a
297. y of sail nutrient Delete an increase in rate of erosion of sail causes an increase in rate of leaching of sail nutrient adecrease in fertility of soil causes a decrease in production of crop an increase in amount of mulching of stubble causes a decrease in rate of erosion of soil planting of strip causes a decrease in rate of erosion of sail planting af cover crop causes a decrease in rate of erosion of soil an increase in availability of aff farm jab causes an increase in scale of migration of farmer an increase in scale of migration of farmer causes a decrease in pressure on forest of population adecrease in pressure on farest of population causes a decrease in intensity of degradation af fores adecrease in intensity af degradation of forest causes an increase in availability of forest_fodder an increase in avallability of forest_fodder causes an increase in amount of animal fadder an increase in availability of private_fodder causes an increase in amount of animal fadder an increase in amount of animal fodder causes an increase in number of animal an increase in scale of migration of farmer causes a decrease in availability of farm labour gt a decrease in availability af farm labour causes a decrease in number of animal gt a decrease in number of animal causes a decrease in availability of animal manure adecrease in availability of animal manure causes a decrease infertility af sail adecrease in amount of

Complete AKT5 manual - The Agroecological Knowledge Toolkit

Contents

Download Pdf Manuals

Related Search

Related Contents