A model - Testing Education
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1. Docun ET ET Mai Swap the process out of memory while it is running e g change focus to another application and keep loading or adding applications until the application under test is paged to disk Leave it swapped out for 10 minutes or whatever the timeout period is Does it come back What si its state What is the state of processes that are supposed to interact with it Leave it swapped out much longer than the timeout period Can you get it to the point where it is supposed to time out then send a message that is supposed to be received by the swapped out process then time out on the time allocated for the message What are the resulting state of this process and the one s that tried to communicate with it Swap a related process out of memory while the process under test is running ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 36 Hunches Models Examples Compete ero ning Troubleshooting Group Insight E xam p eS Specifications Compete for a devise such as a printer Put device in use then try to use it from software under test Start using device then use it from other software If there is a priority system for device access use software that has higher same and lower priority access to the device before and during attempted use by software under test Compete for processor attention Some other process generates an2. Group I nsight Specifications Test the program broadly but not deeply Walk through the program step by step feature by feature Look at what s there Feed the program simple non threatening inputs Watch the flow of control the displays etc ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 26 Hunches Styles of Exploration Example Msn Invariances Ep 8 E Interference Positive esting Eror Handing Troubleshooting Group I nsight Specifications Try to get the program working in the way that the programmers intended tt One of the points of this testing is that you educate yourself about the program You are lookin at it and learning about it from a sympathetic viewpoint using it in a way that will show you what the value of the program Is This is true positive testing you are trying to make the program show itself off not just trying to confirm that all the features and functions are there and kind of sort of working ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 27 Hunches Styles of Exploration Example Teme Invariances E Interference S C e n q g O S Error Handling Troubleshooting Group I nsight Specifications The ideal scenario has several characteristics It is realistic e g it comes from actual cus
3. Interference U S C q S e S Error Handling Troubleshooting Group I nsight Specifications List the users of the system For each user think through the tasks they want to do Create test cases to reflect their simple and complex uses of the system ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 24 Hunches a Styles of Exploration Example rate cE For each Use Case verify ht Sufficient tests positive and negative have been Seen identified for each flow of events for the use cases that traverse your target of test Tests to address any business rules implemented by the use cases ensuring that there are tests inside outside and at the boundary condition value for the business rule Tests to address any sequencing of events or actions such as those identified in the sequence diagrams in the design model or user interface object states or conditions Tests to address any special requirements defined for the use case such minimum maximum performance sometimes combined with minimum maximum loads or data volumes during the execution of the use cases Modified from Rational Unified Process RUP Rational ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 25 Hunches Styles of Exploration Example Msn Tnvariances E Interference Simple Walkthroughs rorranamna Troubleshooting
4. Models models gt 3 i State Model Based Testing s jht Lo O k at Specifications All the possible inputs the software can receive then All the operational modes something in the software that makes it work differently if you apply the same input All the actions that the software can take Do the cross product of those to create state diagrams so that you can see and look at the whole model Example Spent 5 hours looking at the API list found 3 4 bugs then spent 2 days making a model and found 272 bugs The point is that you can make a model that is too big to carry in you head Modeling shows inconsistencies and illogicalities ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 14 Hunche Styles of Exploration Models Models gt Test Management and Techniques ET Plai Docun gt e ling State Transition Diagram File Transfer 3 Application1 Cet Applic requestfile File 1 pp transfer negotiate alleles 1 transfer COMPLETE 1 transfer File ABORTED SHARING violation Invalid file request wer Application Connected Modems negotiate Modems Connected NO appl Connection Dial Server responding Modem responding Off hook NO modem Connection Off hook Server NOT responding Initial state req prep File tran
5. De biasing individual or team Exploratory investigation Risk analysis Bug advocacy ET Workshop v 1 20 J ames satisfice com Skills and Techniques 2002 Amland Consulting 4 52 and dimensional analysis is the process of analyzing the dimensions of something Example dimensional analysis done on a wine glass volume of the glass height of the glass width at it s widest point deviation from perfect circularity mass pieces enumeration of distinct components base stem cup melting point material it s made from age Surface it is currently standing upon sentimental value market value The skill of dimensional analysis is about modelling something in many different ways any of which may figure in how w will test it ET Workshop v 1 20 J ames satisfice com Skills and Techniques 2002 Amland Consulting 4 53 Inferencing Out Loud The ability to talk through a logical progression either forward from evidence to conjecture or backward from conjecture to evidence Using the HICCUPP heuristics ET Workshop v 1 20 Consistent with History Present function behavior is consistent with past behavior Consistent with our Image Function behavior is consistent with an image that the organization wants to project Consistent with Comparable Products Function behavior is consistent with that of similar functions in comparable products Consistent with Claims Function behavior is c
6. and reading for the state that could have led to it and the states that could have led to those The tester imagines a failure instead and asks how to produce it Imagine the program being in a failure state Draw a bubble What would have to have happened to get the program here Draw a bubble for each immediate precursor and connect the bubbles to the target state For each precursor bubble what would have happened to get the program there Draw more bubbles More bubbles etc Now trace through the paths and see what you can do to force the program down one of them ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 10 Hunche Examples Invariances E E Interference Data Relationsnip rer panain Troubleshooting Group I nsight Specifications Styles of Exploration Models Pick a data item Trace its flow through the system What other data items does it interact with What functions use it Look for inconvenient values for other data items or for the functions look for ways to interfere with the function using this data item ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 11 Humche cee Styles of Exploration Models i Procedural Relationships i Pick i aek Specifications Step by step describe how it is done and how it is
7. function behavior is consistent with past behavior Consistent with our Image Function behavior is consistent with an image that the organization wants to project Consistent with Comparable Products Function behavior is consistent with that of similar functions in comparable products Consistent with Claims Function behavior is consistent with what people say it s supposed to be Consistent with User s Expectations Function behavior is consistent with what we think users want Consistent within Product Function behavior is consistent with behavior of comparable functions or functional patterns within the product Consistent with Purpose Function behavior is consistent with apparent purpose ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 50 thought skill is the ability to something more or less Skill varies from person to person It s distinct from talent and know ledge A technique by contrast is a way of doing something a sort of recipe Skill belongs to a person technique is universal J ames Bach Satisfice nc ET Workshop v 1 20 J ames satisfice com Skills and Techniques 2002 Amland Consulting 4 51 Styles of Exploration Summary Skills General systems modelling and dimensional analysis Inferencing out loud Experiment design Technical story telling Use of mnemonics and heuristics
8. handled in the system to as much detail as you know Now look for ways to interfere with it look for data values that will push it toward other paths look for other tasks that will compete with this one etc ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 12 fa Examnles Styles of Exploration Models Functional Relationships oting ht A model what you can do to establish a strategy for 9 cons deciding how to decide what to regression test after a change 1 Map program structure to functions This is or would be most efficiently done as a glass box task Learn the internal structure of the program well enough to understand where each function or source of functionality fits 2 Map functions to behavioral areas expected behaviors The program misbehaved and a function of functions were changed What other behaviors visible actions or options of the program are influenced by the functions that were changed 3 Map impact of behaviors on the data When a given program behavior is changed how does the change influence visible data calculations contents or data files program options or anything else that is seen heard sent or stored ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 13 Styles of Exploration
9. interrupt e g ring into the modem or a time alarm in your contact manager Try to do something during heavy disk access by another process Send this process another job while one is underway ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 37 Styles of Exploration Interference Hunches Models Examples Invariances Styles of Exploration E Interference Error Handling Error Hann piesnooting Group I nsight Specifications Review possible error messages Press the wrong key at the error dialog Make the error several times in a row Device related errors disk full printer not ready etc Data input errors Corrupt files missing data wrong data etc Stress Volume Huge files too many files tasks devices fields records etc ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 38 Hunches Styles of Exploration ae Invariances E Interference Troubleshooting Error Handing up insight Specifications We often do exploratory tests when we troubleshoot bugs Bug Analysis Simplify the bug by deleting or simplifying steps Simplify the bug by simplifying the configuration or background tools Clarify the bug by running variations to see what the problem is Clarify the bug by identifying the version that it entered the product St
10. Exploratory Lest Styles These slides are distributed under the Creative Commons License In brief summary you may make and distribute copies of these slides so long as you give the original author credit and if you alter transform or build upon this work you distribute the resulting work only under a license Identical to this one For the rest of the details of the license see http creativecommons org licenses by Sa 2 0 legalcode ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 1 T 9 Styles of Exploration Outline 1 Introduction 5 Test Management Models and Techniques Hunches Examples ET Planning Exec Invariances and Documentation Interference Error handling ET Styles Troubleshooting Group Insight ET Management Specifications 5 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 2 ee 4 Exploratory Test Styles Skills and Techniques ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting In the fields of observation chance favors only those minds which are prepared Louis Pasteur ET Workshop v 1 20 Mage Piel 2002 Skills and Techniques 2002 Amland Consulting 4 4 Approaches Styles of ET At the heart of all ET styles C Questions and Questioning Skills Characterize the styles with respect to each other a oey focus on Method of questioning Method of describing or analysing th
11. Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 8 Hunche Styles of Exploration Models Eramaa T Architecture Diagrams 9 Work from a high level design map of the system eae Pay primary attention to interfaces between components or groups of components We re looking for cracks that things might have slipped through What can we do to screw things up as we trace the flow of data or the progress of a task through the system You can build the map in an architectural walkthrough Invite several programmers and testers to a meeting Present the programmers with use cases and have them draw a diagram showing the main components and the communication among them For a while the diagram will change significantly with each example After a few hours it will stabilize Take a picture of the diagram blow it up laminate it and you can use dry erase markers to sketch your current focus Planning of testing from this diagram is often done jointly by several testers which understand different part of the system ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 9 Hunche Examnles Styles of Exploration Models Be 3 i Bubble Reverse State Diagram s To trouble shoot a bug a programmer will often work the code backwards starting with the failure state
12. are Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 33 Hunches Models Examples Invariances Sto 0 Error Handling Troubleshooting Group Insight Specifications Styles of Exploration Interference Cancel the task at different points during its completion Cancel some other task while this task is running A task that is in communication with this task the core task being studied A task that will eventually have to complete as a prerequisite to completion of this task A task that is totally unrelated to this task ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 34 Hunches Models Examples Invariances P ause Error Handing Troubleshooting Group Insight Specifications Styles of Exploration Interference Find some way to create a temporary interruption in the task Pause the task For a short time For a long time long enough for a timeout if one will arise Put the printer on local Put a database under use by a competing program lock a record so that it can t be accessed yet ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 35 Hunches Styles of Exploration Interference Models Swap out of memory seyis Troubleshooting Group I nsight Specifications an ET Plai
13. e product The details of the product The patterns of use of the product The environment in which the product is run To what extent would this style benefit from group interaction ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 5 ET Workshop v 1 20 Styles of Exploration Hunches Models Examples Invariances Interference Error Handling Troubleshooting Group Insight Specifications Gota From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 6 Hunches gt case Examples invariances Interference H U n h e S Error Handling Troubleshooting Group I nsight Specifications Styles of Exploration Random Questioning Similarity to previous errors Following up gossip and predictions Follow up recent changes P ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 7 Hunche Examples Invariances Interference M O q S Error Handling Troubleshooting Group I nsight Specifications Styles of Exploration Architecture diagrams Bubble diagrams Data relationships Al mi Procedural relationship Model based testing state matrix Va Requirements definition Functional relationship for regression testing Failure models p 2 d dI ET
14. es Find alternate ways to violate internal data constraints How to Break Software Whittaker et al 2000 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 20 Hunche cee a Styles of Exploration Failure Models ce ac How to Break Software 5 s ht Specifications Computation Attacks Experiment with invalid operand and operator combinations Force a function to call itself recursively Force computation results to be too large or too small Find features that share data or interact poorly How to Break Software Whittaker et al 2000 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 21 Exercise 3 Select a different area of StarOffice or continue where you left if you prefer and are productive or Select defect handling in MiniTest Create a charter including a mission and select a different testing style and continue to test the AUT ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 22 Hunches Styles of Exploration Teme Tnvariances Interference F Xa A D e S Error Handling Troubleshooting Group I nsight Specifications Use Cases Simple Walkthroughs Positive Thinking Scenarios Soap Operas gt ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 23 Hunches Styles of Exploration Example enema Invariances
15. hop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 45 Hunches Styles of Exploration suai Invariances Interference Specifications Error Handling Troubleshooting oom Tine t Active reading Tripos Active reading Ambiguity analysis User Manual Consistency Heuristics ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 46 Hunches Models Examnles ET e c Active Reading Developing Questions Satisfice Testing Model lt Specieatons gt When you run out of testing ideas walk the chart looking for a project product quality factor that you haven t based a test on recently Randomly combine project product quality factors make up a test case that Is influenced by the selected product factor that test the selected product element against the selected quality criterion Analyze a specification operating on the assumption that every statement defines a project factor a product factor or a quality criterion ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 47 Hunches awe Styles of Exploration Specifications aceite 5 r Active Reading Ambiguity Analysis s ht There are all sorts of sources of ambiguity in software Tda desig
16. isfice com Skills and Techniques 2002 Amland Consulting 4 56 Exercise 4 Select a different area of StarOffice or MiniTest or continue where you left off if you prefer and are productive or Select WEB site www amland no et_test Create a charter including a mission and select a different testing style and continue to test the AUT ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 57 Hunches Test Management Models and Techniques Examples ET Planning Exec Invariances and Documentation Interference Error handling Troubleshooting Group Insight Specifications ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 58
17. lysis technique Given that the system has shown a specific failure you work backwards through precursor states the various paths that could conceivably lead to this observed failure state As you walk through you say that Event A couldn t have happened unless Event B or Event C happened And B couldn t have happened unless B1 or B2 happened And B1 couldn t have happened unless X happened etc While you draw the chart you look for ways to prove that X whatever a precursor state could actually have been reached If you succeed you have found one path to the observed failure Styles of Exploration Group Insight ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 44 Hunches Models Examnles Styles of Exploration Group Insight Paired Exploratory Testing oting jht See previously presentation on testing in pairs section sono 3 2 Exploratory Testing in Pairs Developed independently of paired programming but many of the same problems and benefits apply The eXtreme Programming community has a great deal of experience with paired work and offers many lessons Kent Beck Extreme Programming Explained Ron Jeffries Ann Anderson amp Chet Hendrickson Extreme Programming Installed Laurie Williams of NCSU does research in pair programming For her publications see http collaboration csc ncsu edu laurie ET Works
18. n and development In the wording or interpretation of specifications or standards In the expected response of the program to invalid or unusual input In the behavior of undocumented features In the conduct and standards of regulators auditors In the customers interpretation of their needs and the needs of the users they represent In the definitions of compatibility among 3 4 party products Whenever there is ambiguity there is a strong opportunity for a defect at least in the eyes of anyone who understands the world differently from the implementation ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 48 Hunches Models Examples Invariances Styles of Exploration Specifications l nterference User Manual lesan Troubleshooting iaht Specifications gt Write part of the user manual and check the program against it as you go Any writer will discover bugs this way An exploratory tester will discover quite a few this way ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 49 Hunches ave Styles of Exploration Specifications cree Ee Invariances Docun ET Interference ET Mai Consistency Heuristics ramo Troubleshooting oom Tine t Discussed previously HICCUPP Spectators Consistent with History Present
19. ndle large files Mathematical operations in different but equivalent orders ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 30 Hunches Styles of Exploration Models Interference mtn Troubleshooting Group I nsight Specifications Interrupt Change Stop Pause Swap Compete gt ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 31 Hunches Models Examples Lnterrupt Tra rario Troubleshooting Group Insight Specifications Styles of Exploration Interference Generate interrupts From a device related to the task e g pull out a paper tray perhaps one that isn t in use while the printer is printing From a device unrelated to the task e g move the mouse and click while the printer IS printing From a software event ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 32 Hunches Models Examples Invariances Change Error Handling Troubleshooting Group Insight Specifications Styles of Exploration Interference Change something that this task depends on Swap out a floppy Change the printer that the program will print to without signaling a new driver Change the video resolution ET Workshop v 1 20 From Black Box Softw
20. ns Collect even more bugs classify them and refine the attacks How to Break Software Whittaker et al 2000 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 17 Cea x Styles of Exploration Failure Models bat gist Examnles ET Plai Docun me i How to Break Software 2 i Input Constraint Attacks DE Force all error messages to occur Apply inputs that force default values Explore character sets and data types Overflow input buffer Find inputs that may interact e Test various combinations of their values Repeat the same inputs many times How to Break Software Whittaker et al 2000 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 18 Styles of Exploration Failure Models Models gt bat gist Examnles ET Plai Docun me i How to Break Software 3 3 oting ht Specifications Output Constraint Attacks Force different outputs for each input Force invalid outputs Force output size change Force output to exceed output space Force the screen to refresh How to Break Software Whittaker et al 2000 ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting 4 19 Styles of Exploration Failure Models Models gt Examnles How to Break Software 4 Storage Constraint Attacks Apply inputs under differing initial conditions Data Structure Over Underflow Force a data structure to store too many or too few valu
21. ons Styles of Exploration Group Insight Summary of Example You brainstormed a list of tests for the two variable two digit problem e The group listed a series of cases test case why You then examined each case and the class of tests it belonged to looking for a more powerful variation of the same test e You then ran these tests You can apply this approach productively to any part of the system ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 42 Hunches Styles of Exploration Group Insight Models Examnles Test Mana ET Plai Docun ET Group Discussion of Related Components oting l ht Specifications The objective is to test the interaction of two or more parts of the system The people in the group are very familiar with one or more parts Often no one person is familiar with all of the parts of interest but collectively the ideal group knows all of them The group looks for data values timing issues sequence issues competing tasks etc that might screw up the orderly interaction of the components under study ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 43 Hunches Models Examples Invariances Interference Fishbone AnalysiS rorreramo Fishbone analysis is a traditional failure ana
22. onsistent with what people say it s supposed to be Consistent with User s Expectations Function behavior is consistent with what we think users want Consistent within Product Function behavior is consistent with behavior of comparable functions or functional patterns within the product Consistent with Purpose Function behavior is consistent with apparent purpose J ames satisfice com Skills and Techniques 2002 Amland Consulting 4 54 Styles of Exploration Summary Skills General systems modelling and dimensional analysis Inferencing out loud Experiment design Technical story telling Use of mnemonics and heuristics De biasing individual or team Exploratory investigation Risk analysis Bug advocacy ET Workshop v 1 20 J ames satisfice com Skills and Techniques 2002 Amland Consulting 4 55 Heuristics and rules and Skills ll werelate to heuristics as a tool to apply something that might help us do the right thing in a given situation whereas werelate to a rule as something to comply with something that defines right behavior U sing heuristics properly requires that you exercise discretion and judgment on some level whereas judgment may get in the way of rules I t s helpful to have contradictory heuristics because that s like having a variety of advice available before making a decision whereas contradictory rules make compliance impossible ET Workshop v 1 20 J ames sat
23. rengthen the bug with follow up tests using repetition related tests related data etc to see if the bug left a side effect Strengthen the bug with tests under a harsher configuration Bug regression vary the steps in the bug report when checking if the bug was fixed ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 39 Hunches Models Examples Invariances Interference Group Lnsig ht Era raie Styles of Exploration Brainstormed test lists Group discussion of related components Fishbone analysis Paired Exploratory Testing ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 40 Hunches Models Styles of Exploration Group Insight ARCA Brainstormed test Lists oting Specifications Example copy Here is the program s specification This program is designed to add two numbers which you will enter Each number should be one or two digits The program will print the sum Press Enter after each number To start the program type ADDER Before you start testing do you have any questions about the spec ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 41 Hunches Models Examnles Brainstormed est Lists oting Specificati
24. sfe Application 1 will request download of file Example a lt ET Workshop v 1 20 Skills and Techniques 2002 Amland Consulting Com Modem Failure NOT Tech responding Failure Appl Failure Hunche Examples Invariances Styles of Exploration Models E Interference Failure Model Error Hain Troubleshooting Group I nsight Specifications Whittaker Why Software Fails 1999 2002 The Fundamental cause of software errors Constraint violations Input constraints Such as buffer overflow Output constraints Computations Look for divide by zeros and rounding errors Figure out inputs that you give the system that will make it not recognize the wrong outputs Data violations Really good for finding security holes ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 16 Hunche cee a Styles of Exploration Failure Models ce ac How to Break Software 1 ht Specifications Being a tester means finding bugs efficiently Set clear goals for every test case Understand where bugs might hide Know how to expose them The method Collect and study a large number of bugs in released products Understand why they occur and what type of test it would take to find them Generalize the test into attack patterns and teach students how to execute these patter
25. tomer or competitor situations There is no ambiguity about whether a test passed or failed The test is complex that is it uses several features and functions There is a stakeholder who will make a fuss if the program doesn t pass this scenario ET Workshop v 1 20 From Black Box Software Testing copyright 1996 2002 Cem Kaner Skills and Techniques 2002 Amland Consulting 4 28 Hunches Styles of Exploration Example Scenarios enema Invariances Interference S Oa 0 Q 0 eras Error Handling Troubleshooting Group I nsight Specifications Build a scenario based on real life experience This means client customer experience Exaggerate each aspect of it Example for each variable substitute a more extreme value Example if a scenario can include a repeating element repeat it lots of times Make the environment less hospitable to the case increase or decrease memory printer resolution video resolution etc Create a real life story that combines all of the elements into a test case narrative ET Workshop v 1 20 Cem Kaner referensing Hans Buwalda 2001 Skills and Techniques 2002 Amland Consulting 4 29 Hunches Models Examoles n Tern E Invariances she Troubleshooting Group I nsight Specifications Styles of Exploration Making changes that should NOT affect the program Examples Sending text and graphics in different orders to a printer Using VERY large files with programs that should ha
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