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Resource Guide for Accessible Design of Consumer Electronics

1. Unfortunately the guidelines contained in this document do not address specific cognitive limitations rather they may apply generally to some of the cognitive impairments described 23 Vanderheiden amp Vanderheiden 1991 22 Resource Guide for Accessible Design of Consumer Electronics 5 Functional Limitations Speech and Language Limitations The final category of functional limitation is speech and language limitations Often these limitations are related to perceptual or cognitive limitations but they can also be due to other physical problems such as illness or injury Individuals with speech and language limitations have difficulty in the comprehension and or the expression of spoken or written language Individuals with dyslexia have problems interpreting written language Aphasia is a cognitive impairment or learning disability that affects communication through speech writing and signs Dysarthria refers to slurred speech due to impairment of the tongue or other muscles essential to speech Individuals may also have stuttering problems or even a complete loss of speech Individuals with speech and language limitations have difficulty using products that require voice communication such as the telephone or other telecommunications systems Designers of systems that use voice input should consider providing alternate methods of control Consumer electronics designers should consider providing both text and speech output thi
2. Error message phrasing consistency and duration Error messages should be phrased politely should not place fault use patronizing language or attempt to be humorous Use the same error message each time the same error occurs but do not use the same generic error message for a broad class of related but distinctly different errors Do not permit error messages to remain on the screen after the error has been corrected REFERENCE Brown 1988 118 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 5 0 Accessories and Modifications There are millions of product users that have some sort of impairment In the event that products can not be made accessible in the original design efforts should be made to create accessories and accommodate modifications to consumer products to make them more accessible to this population There are already several types of accessories available for the different disabled groups Every effort should be made to ensure that products are compatible with these existing accessories Ideally the accessory that would work best with the product should be provided with the product or available as an option At the very least there should be some information telling the user where to obtain the available accessories Some of the accessories are listed below Accessories for Visual Impairments Accessories for Physical Impairments e magnifiers e mouthsticks e bright lightin
3. FOREWORD The primary goal of commercial product design is to maximize market share Today one factor contributing to market share is the increasing number of potential customers who experience functional limitations as a result of aging or disabling conditions A growing body of research suggests that there are ways to design products that can accommodate functional limitations and actually enhance their ease of use for a wider audience of customers and users The electronics industry has long been receptive to improving the accessibility or usability of consumer products for people with disabilities and persons experiencing functional limitations However achieving accessible designs given short product development intervals and the difficult testing of new product concepts and features presents a major challenge to both product managers and designers To address these and other related challenges the Electronic Industries Association has developed accessible design guidelines for easy reference during the design and feature specification process This document is informational in nature only and is intended to assist designers efforts to make their products more accessible It represents the compilation of information from many sources and as a working document is under continual revision The Association believes these guidelines will serve consumer product manufacturers well in the long term goal of creating products that address th
4. Nielsen J 1993 Usability Engineering San Diego Academic Press Inc Nielsen J and Mack R L eds 1994 Usability Inspection Methods New York John Wiley amp Sons Inc Norman D 1988 The Psychology of Everyday Things New York Basic Books Inc Scadden L 1994 Design for Everyone A Series of Articles reprinted from CE Network News EJA s news monthly on consumer electronics Washington D C Electronic Industries Association Schneiderman B 1987 Designing the User Interface Strategies for Effective Human Computer Interaction Reading MA Addison Wesley Publishing Company Smith S and Mosier J 1986 Guidelines for Designing User Interface Software Report No ESD TR 86 278 Bedford Massachusetts The MITRE Corporation Sanders M S amp McCormick E J 1987 Human Factors and Engineering Design New York McGraw Hill Inc Salvendy G 1987 Handbook of Human Factors New York John Wiley amp Sons Trace Research and Development Center Excerpts Regarding Access to Next Generation Information Systems taken from a recent Trace Center Proposal Madison WI Waisman Center Trace Research and Development Center Vanderheiden G and Vanderheiden K 1991 Accessible Design of Consumer Products Guidelines for the Design of Consumer Products to Increase their Accessibility to People with Disabilities or who are Aging Working Draft 12 91 Compiled for the AD HOC
5. 1991 83 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 17 1 17 1 1 17 2 1 17 3 1 17 4 Controls Auditory Input 1 17 1 17 4 Auditory Input Use speech recognition for complex information entry tasks that must be performed concurrently with other visual or manual tasks Avoid voice entry in stressful applications or in noisy environments COMMENT Voice entry should be used in only low to moderate noise environments less than 85 dB SPL REFERENCE Brown 1988 Salvendy 1987 Voice recognition algorithms Where feasible incorporate adaptive voice recognition algorithms into the operation of the system In any case provide for updating of voice templates during operation of the system REFERENCE Salvendy 1987 Recognition errors Because the severity of consequences of recognition errors varies depending on the application consider the relative importance of different types of errors for a particular application EXAMPLE In a recording environment the consequences of miss recognizing the word record might be monetarily high where for recreational purposes the cost would be significantly less REFERENCE Salvendy 1987 Message length Minimize message length to improve message recognition rate REFERENCE Salvendy 1987 Vocabulary size Speech recognition systems have lower recognition accuracy and slower processing when the vocabulary size is large In ord
6. Width of two strokes between lines il E E Ie 2 3 4 Type lar Simple letters and symbols sans serif Has no similar confusable characters E E E E Ee E i Case Combination of upper and lower case 2 3 6 Abbreviations and Acronyms a Only where necessary Common and familiar formats only 2 3 7 Sentence style a Short concise and distinct wording Affirmative and in active voice Brightness Contrast and Refresh Rate Brightness Contrast Ratio between 6 1 to 15 1 Contrast Adjustment Provides adequate contrast adjustment Brightness Adjustment Provides adequate brightness adjustment Ei ie Ei 2 4 4 Brightness Coding ae Uses only two brightness settings as a code Zz ee E E Illumination Not exceeded by ambient or back lighting Reduction of Glare Uses non reflective surfaces 2 4 7 Refresh Rate Avoid flicker rates of 10 25 Hz 38 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines S M U Graphics and Icons 2 5 1 Appearance See guidelines 2 3 1 and 2 4 1 2 4 7 for brightness size and contrast 2 5 2 Symbols distinguishable from other symbols Only identifying features shown minimal detail Identification Simple concrete graphics 26 Color S OE 6 1 Amount of Color Conservative use of color Fewer than five different colors for coding 6 2 Color Differentiation Bl
7. 1987 Mounting rotary controls Rotary controls that are mounted tother one on top of the other or one around the other are referred to as gang mounted controls Rotary selector controls should not be gang mounted Gang mounting increases both cognitive and dexterity demands REFERENCE EIA 1994 Honeywell Inc 1992 Sanders and McCormick 1987 Continuous rotary controls For continuous rotary controls e coarse setting 180 degrees of knob rotation should produce 6 inches of movement on a corresponding linear scale e fine setting 180 degrees of knob rotation should produce 1 to 2 inches of movement on a corresponding linear scale REFERENCE EIA 1994 Honeywell Inc 1992 Sanders and McCormick 1987 Direction of movement In order to increase move to the right or to move up you should turn the control clockwise In order to decrease move to the left or to move down you should turn the control counter clockwise REFERENCE Cushman and Rosenberg 1991 EIA 1994 Tactile Features You should always include grooves serrations or scallops on the control In addition the position of a rotary control will be enhanced by the addition of a tactile indicator such as a notch a raised dot or a pointer COMMENT Including grooves serrations or scallops on the control may make it easier for impaired users to exert more force REFERENCE EIA 1994 Kanis 1993 75 Resource Guide for Accessible Design of Consumer Electron
8. 2 Height to Width Ratios 1 0 7 to 1 0 9 for fixed column resentation 1 0 5 to 1 1 for proportionally spaced text 3 Stroke width at 1 12 character height 3 2 1 5 Visibility Visible in all expected viewing conditions Fee T DN Not for radio Labels are too small 2 3 3 Spacing Width of one stroke between characters Width of one letter between words Width of two strokes between lines 50 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example Guidelines 2 3 4 Type Simple letters and symbols sans serif Has no similar confusable characters S 2 3 5 Case Combination of upper and lower case E v 2 3 6 Abbreviations and Acronyms Only where necessary Common and familiar formats only Step 3 Trade offs and Recommendations After the checklist evaluation has been completed several recommendations for improvement of the product should be listed In situations where it is not clear from the checklist what improvements are needed the actual guidelines should be referenced since they contain more detailed information and examples For example checklist item 1 5 1 suggests that the pushbutton centers should be dished The checklist evaluation showed that the top buttons were not dished As a further analysis the guideline 1 5 1 on page 64 was referenced This guideline lists several methods of ensuring that pushbutton surfaces are tactually dist
9. FM 5460 70 80 100 120 140 10 aT x C of 88 92 98 102 103 108 on FM Left Side Alarm Time Set Display Lome Hour cy Lock Bright 53 Resource Guide for Accessible Design of Consumer Electronics 9 References 9 REFERENCES In the creation of the guidelines for this document many of the references used specifically addressed design for the disabled Other references however provided generic guidelines for all users Guidelines were taken from the more general documents when implementation of the guidelines was believed to improved the accessibility of a product Design guidelines in this document that reference guidelines applicable to all users often have comments that indicate the expected applicability of the guideline to disabled users Bailey R W 1989 Human Performance Engineering Using human factors ergonomics to achieve computer system usability Englewood Cliffs NJ Prentice Hall Brown C B 1988 Human Computer Interface Design Guidelines Sunnyvale CA Ablex Publishing Corporation Cushman W H and Rosenberg D J 1991 Human Factors in Product Design New York Elsevier Day R and Kensinger J 1995 Final Report on Two Focus Groups About Issues Related to Assistive Devices Bethesda MD RIVA Market Research Inc Electronic Industries Foundation 1993 EIA Seal of Accessibility Committee Development Plan Version 1 0 9 15 1993 Electronic Industries Foundation 19
10. General 3 2 Tones and Beeps 3 3 Synthesized or Recorded Speech 3 4 Warning Signal Characteristics 104 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 3 1 Auditory Displays General 3 1 3 1 3 General When to use auditory displays Auditory displays are appropriate under the following circumstances e The intended audience is visually impaired e The message is simple and short e The message will not be referred to later e The message requires an immediate or time based response e There is no room for another visual display or the number of visual displays overloads the pilot s attention and processing resources e Redundant display of information is desirable e The population stereotype for the mode of presentation is an audio display e The environment is dark e The user moves about continuously in relation to the product EXAMPLE Warning devices and alarms are often best presented as auditory displays redundant visual displays should also be provided for the hearing impaired in the case of emergencies REFERENCE Cushman and Rosenberg 1991 Tonal Messages Use tonal signals for indicating status conveying warnings and displaying qualitative information COMMENT Tonal signals should be used in any of the following situations e immediate responses from the listener is required e the listener must be alerted that a spoken message is about to follow e noise condi
11. Honeywell Inc 1992 80 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 14 1 14 1 1 14 2 1 14 3 Controls Mouse 1 14 1 14 3 Mouse A mouse is unusable by blind product users unless audio feedback for cursor position is provided continuously The mouse should easily fit into the palmar grasp of the hand with a rounded rather than an angular back The mouse s top front surface should be as wide or wider than the back of the mouse so fingers can spread naturally The mouse buttons should be on the front surface rather than on top REFERENCE EIA 1994 Helander 1988 Tactile features The top surface of the mouse should be a matte texture to prevent glare and the sides of the mouse should be a highly textured gripping surface REFERENCE Helander 1988 Feedback Mouse buttons should provide good tactile and auditory feedback of their activation REFERENCE Helander 1988 Accidental Activation Mouse buttons should be stiff enough to support resting fingers without activation REFERENCE Helander 1988 81 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 15 1 15 1 1 15 2 Controls Trackball 1 15 1 15 2 Trackball A trackball is unusable by blind product users unless audio feedback for cursor position is provided continuously The trackball gain should be adjustable for both coarse and fine movement REFERENCE FIA 199
12. TV for people who are deaf or experience a loss of hearing to use telephones and automated telephone services and for people with mobility or dexterity limitations to meet the challenges of their environment and become independent and productive This document addresses the following functional limitations e Mobility and dexterity limitations e Deafness and hearing loss e Blindness and low vision e Speech limitations e Perceptual and cognitive limitations Resource Guide for Accessible Design of Consumer Electronics 1 Introduction Cognitive limitations are discussed in Chapter 5 on Functional Limitations however because of problems associated with accounting for the wide range of cognitive limitations and the lack of available references specific types or degrees of cognitive limitations are not addressed There are however a number of guidelines that will help lead to products that are easier to use in general and may make products more accessible to individuals with cognitive limitations Quantifying the prevalence of various functional limitations underscores the size of the market that is realized when products are designed to be more accessible and provides designers with information needed to determine how to focus designs to include the widest range of individuals Approximately 31 6 million people in the U S suffer from rheumatic diseases arthritis As many as 22 million people in the U S have hearing impairments and abou
13. apparent cues should be provided that indicate to the user how to access the functions For example labels on control panel covers or menu labels provide cues that more functions are available Many designers choose to hide functions that are designed specifically for disabled populations so that they are invisible to the average user Of course this makes it difficult for the disabled population to access or even be aware of the functions In this situation designers should ensure that there are mechanisms for informing potential disabled users of the availability of these functions df Norman 1988 15 Resource Guide for Accessible Design of Consumer Electronics 4 General Design Principles 5 Provide Adequate Feedback Products should provide immediate and meaningful feedback for system events The feedback should be direct and conspicuous Redundant feedback such as both tactile e g mechanical detents and auditory indications that a control has been activated or both auditory and visual error indications should be used to make designs more accessible Feedback should be provided for error messages identifications and settings and mode indications A visual indication of volume is useful feedback for the hearing impaired Shaped pointers recessed or protruding dots or notches provide useful feedback for the visually impaired 6 Make the Design Forgiving Consumer products should be designed so that they reduce the possibi
14. coding When location is used as a method of coding the separation between the controls should be e at least 2 5 inches 6 3 cm for vertically arranged switches e at least 4 inches 10 2 cm and preferably more for horizontally arranged switches REFERENCE Sanders and McCormick 1987 Pictorial Symbols The maximum number of different pictorial symbols to use is 10 REFERENCE Cushman and Rosenberg 1991 62 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 3 1 3 1 1 3 2 1 3 3 1 3 4 Controls Separation 1 3 1 3 4 Separation Controls should be spaced far enough apart and away from adjacent structures to permit adequate grasping and manipulation through an entire motion range COMMENT Users with mobility and dexterity limitations may need to grasp a control with their hand s If adequate separation between controls is provided using the product will be much easier for those users REFERENCE Bailey 1989 Pushbuttons The optimal separation between pushbutton controls is 1 2 the width of the control If the pushbutton is small there should be at least 3 4 inch and optimally 2 inches between buttons COMMENT A larger separation between pushbuttons will be beneficial to both mobility impaired and vision impaired users REFERENCE EIA 1994 Salvendy 1987 Rotary Knobs The separation between rotary knobs should be at least 1 inch or 2 5 cm and optimally 2 inches
15. feedback REFERENCE EIA 1994 Honeywell Inc 1992 1 5 4 Separation There should be 0 5 to 2 0 inches between pushbuttons for finger operation and a minimum of 6 inches for palm activated pushbuttons COMMENT The separation between pushbuttons can be reduced to 0 25 inches if there are several buttons in an array and they all have a similar function or are to be operated in a sequence EXCEPTION When designing for mobility impaired users always choose the larger separations even if there are several buttons in an array This will make it easier for those users to activate the correct button REFERENCE Cushman and Rosenberg 1991 EIA 1994 1 5 5 Size Increasing the size of pushbuttons may allow more force to be exerted by using both hands The following sizes are recommended e at least 0 5 to 1 0 inches in diameter or square for finger activation e at least 1 0 to 3 0 inches in diameter or square for palm activation COMMENT The larger the button the more likely mobility impaired users will be able to use them REFERENCE EIA 1994 Honeywell Inc 1992 Kanis 1993 1 5 6 Force The force required to activate the pushbutton should be between 10 to 20 oz for finger activation and between 10 to 80 oz for palm activation In addition the force required to deactivate should be about 40 lower than the activation force COMMENT The amounts given should be used as maximums Mobility impaired users will have a hard time act
16. groups of data COMMENT The information should not be combined into more than five groups Research has shown that search time increases when the number of groups is large COMMENT Minimize the number of groups by making each group as close to 5 degrees as is feasible COMMENT Use attention attracting and grouping techniques such as highlighting coloring or graphical boundaries around key information REFERENCE Helander 1988 Honeywell Inc Vol 25 6p 657 682 Tullis 1983 Vanderheiden and Vanderheiden 1991 Justification Words and alphanumeric data should be left justified whereas numeric data should be right justified on the decimal point REFERENCE Tullis 1983 Honeywell Inc Vol 25 6p 657 682 Wright and Barlow 1995 102 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Information Presentation 2 8 5 2 8 7 2 8 5 Simplicity The language and layout of the display should be as simple as possible to help readability and comprehension by all users COMMENT If simple screen layouts cannot be created provide the user with the option to look at one thing at a time COMMENT Shorten menus and hide layer seldom used commands COMMENT Use Arabic rather than Roman numerals and put the most important information at beginning of written text COMMENT Keep auditory presentations short REFERENCE Vanderheiden and Vanderheiden 1991 2 8 6 Use symbols and wo
17. in hours and minutes or in minutes and seconds To change the display to minutes and seconds slide the switch on the left side of the clock radio to the SEC position The time can be set using the same TIME SET buttons as for the alarm However before the time can be set the TIME SET LOCK switch must be moved to the ON position The brightness of the time display can also be changed using the rotary knob labeled DISPLAY Step 1 Initial Heuristic Evaluation The first step of the evaluation is to perform an initial heuristic evaluation by walking through each of the functions of the alarm clock and noting potential problems In stepping through the functions several potential problems for individuals with functional disabilities are noted First the slide switches do not move easily between positions This is potentially troublesome for the four setting SELECTOR slide switch since there are four settings and there is not a hard stop for the middle positions as there is for all the two setting slides Second the slide switch on the bottom is difficult to access because of its position the radio must be lifted and it is difficult to operate because the switch is recessed Third it is somewhat difficult to set the alarm because the alarm button must be held down while pressing either the fast or slow buttons Finally the labels on the clock radio are small especially those in the radio display The labels on t
18. of a heuristic evaluation is a list of potential usability problems It is not sufficient for an evaluator to say they do not like something they need to be able to specifically state what feature of the design is problematic and why 27 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Checklist One way of performing a heuristic evaluation is to use a checklist An evaluation checklist should be viewed as a helpful tool that outlines the major points to be considered when designing electronic products that are accessible to users of a wide range of capabilities The following checklist may be used in a heuristic evaluation of products to assure accessibility This checklist summarizes all of the design guidelines in Part 3 for controls visual displays auditory displays and documentation to be used by designers and developers of electronic products The information provided in Part 3 on Accessories and Modifications is not included in this checklist Designers that are planning on using accessories or modifications to their products to make them accessible to the disabled should refer to that section of the Design Guideline Reference Part 3 This checklist was designed to be used in conjunction with the Road Map in Chapter 6 and the design guidelines in the Design Guideline Reference Designers should use the Road Map to help them identify applicable checklist items for their evaluat
19. out when the contrast ratio is low Yellow or green characters on a black background are preferred for visual displays COMMENT The color blue is very difficult for some color blind users to distinguish from background text Therefore saturated blue should not be used to convey important information but can be an excellent background color COMMENT Use combinations of colors such as blue green and violet and contrasting background colors with care EXAMPLE Display yellow letters on a blue background rather than a white background RELATED GUIDELINE 1 2 7 REFERENCE Brown 1988 Haigh 1993 EIA 1994 Salvendy 1987 Vanderheiden and Vanderheiden 1991 97 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Color 2 6 3 2 6 5 2 6 3 Effective Color Use Color Coding Use color for search tasks highlighting or status indications and use similar colors for related data Consider using color coding when the display is unformatted symbol density is high and the operator must search for specified information To use color effectively consider the following e the impact of the selected color code on the legibility of the displayed data e the cognitive effects of the color code on the performance of the user s tasks e the impact of the capabilities and limitations of the display medium RELATED GUIDELINE 2 6 4 REFERENCE Brown 1988 Salvendy 1987 2 6 4 Redundancy To e
20. pushbutton for the record control on a VCR that is both colored and textured differently from other controls will be more easily identified by all users especially the visually impaired Shape Controls should have shapes that are discriminable by touch and that are associated with their function The maximum number of shapes that should be used is 15 but it is recommended to only use five different shapes on any one product COMMENT Controls are easier to learn when they have shapes that are associated with their function REFERENCE Cushman and Rosenberg 1991 Sanders and McCormick 1987 Texture There are three different textures with good discrimination between them They are e smooth e fluted e knurled COMMENT These three different textures are especially useful when used for discriminating between flat cylindrical knobs REFERENCE Sanders and McCormick 1987 Size Size coding in general is not as useful as shape coding a combination of size coding and texture coding is desirable When size coding is used the sizes should be discriminable from each other and a maximum of 3 different sizes is recommended COMMENT Knobs that differ by 1 2 inch 12 7 mm in diameter and by 3 8 inch 9 5 mm in thickness can be accurately discriminated between REFERENCE Cushman and Rosenberg 1991 Sanders and McCormick 1987 Redundant color coding Under low illumination colors may be hard to discriminate therefore color should be u
21. you undecided about the mode of presenting on Mouse 2 1 3 1 1 4 1 information to the user e g visual auditory tactile More than a single or simple word or symbol 7 Does your product have any auditory output Tones or beeps For warning purposes Speech or music Does your product include any written documentation including on line and labels On line information Labels After exhausting all possibilities of making your product directly accessible is your product unable to accommodate specific populations 10 Are you specifically trying to accommodate any of the d following functional limitations 5 3 4 5 7 10 En 1 1 4 1 17 2 1 2 8 3 1 3 4 1 4 2 5 0 1 17 2 1 2 7 3 1 3 4 5 0 5 1 5 3 5 4 5 6 1 1 1 2 1 4 2 1 2 3 6 2 3 7 2 5 2 6 2 7 3 2 7 4 2 7 9 2 8 3 1 1 3 1 3 3 1 9 3 2 3 3 2 4 3 3 3 4 4 1 4 2 3 4 2 8 4 2 10 4 3 5 0 1 17 2 1 17 5 1 17 6 4 2 8 4 2 10 5 0 Mobility and dexterity limitations Hearing limitations Perceptual and cognitive limitations Speech and language limitations 25 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist 7 DESIGN EVALUATION AND CHECKLIST There are several ways that a product can be evaluated Some of those include direct observation interviews questionnaires walkthroughs focus groups heuristic evaluations and usability testing Depending on the desired in
22. 4 Feedback A trackball provides tactile feedback from the balls rotation and speed REFERENCE FIA 1994 Size A trackball should be 2 to 5 inches in diameter and have 100 degrees surface exposure When using a trackball the palm wrist clearance should be 4 75 inches the clearance around the ball should be 2 inches REFERENCE FIA 1994 82 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 16 1 16 1 1 16 2 1 16 3 1 16 4 1 16 5 Controls Foot Controls 1 16 1 16 5 Foot Controls Foot Pushbuttons For foot pushbuttons use elastic resistance aided by static friction to support the foot The resistance should start low build up rapidly and then drop suddenly REFERENCE Sanders and McCormick 1987 Foot Pedals Foot pedals should return to null position when the force is removed Elastic resistance should be provided REFERENCE Sanders and McCormick 1987 Displacement Foot pedals operated by the entire leg should have 2 to 4 inches displacement A displacement of 3 to 4 inches or more should have a resistance of 10 pounds or more Foot pedals operated by ankle action should have maximum displacement of 2 5 inches REFERENCE Sanders and McCormick 1987 Separation There should be 4 inches separating foot pedals REFERENCE Cushman and Rosenberg 1991 Force Foot pedals should require between 64 and 320 oz of force to activate REFERENCE Cushman and Rosenberg
23. 6 1 10 7 1 10 8 1 10 9 1 10 10 1 10 11 1 11 1 11 1 1 11 2 1 11 4 1 11 5 1 11 3 uidelines Direction of movement Clockwise to increase counter clockwise to decrease Tactile Features Grooves serrations or scallops included Tactile indicator i e pointer included Discrete detented controls Approximately 30 angular travel between detented positions Feedback Adequate visual auditory and or tactile feedback Elastic resistance Increases then decreases and snaps into position at detent Settings Stops at beginning and end of range Separation Minimum of 2 between controls Size From 375 to 4 in diameter From 0 625 to 3 0 high Force 12 48 oz of force to activate Slide Switches Maximum of two postions for discrete detented switches Serrated switch top No spring returns Movement of control up away or right increases Feedback Adequate proprioceptive auditory visual and or tactile feedback provided Separation Minimum of 1 inch separating switches Size 0 5 above the surrounding surface 0 25 to 1 0 wide Force From 10 16 oz for activation Accidental Activation Sufficient static friction to reduce error BERR SSR ee eee TTT TTT TT Tt ty TTT l e 34 7 Design Evaluation and Checklist Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines S M U Comments 1 12 Toggle Switches Series of switches in hor
24. 94 EIA Seal of Accessibility Committee Accessible Design Guidelines Issue 0 2 1 8 94 Gibler C Kall D Kasday L and Gawley D 1994 The Accessible Design Process An AT amp T Perspective for Technology and Disability Journal Griffith D 1990 Computer access for persons who are blind or visually impaired Human factors issues Human Factors 32 4 467 475 Haigh R 1993 The ageing process A challenge for design Ergonomics 24 1 9 14 Helander M ed 1988 The Handbook of Human Computer Interaction New York Elsevier Science Publishers B V Honeywell Inc May 1992 Human Factors Design Guidelines for the Elderly and People with Disabilities Revision 3 Draft Minneapolis MN Honeywell Inc Sensor and System Development Center 54 Resource Guide for Accessible Design of Consumer Electronics 9 References Kaplan D and De Witt J 1993 or 1994 Telecommunications and Persons with Disabilities Building the Framework The Second Report of the Blue Ribbon Panel on National Telecommunications Policy Oakland CA World Institute on Disability Kaplan D De Witt J and Steyaert M around 1990 Telecommunications and Persons with Disabilities Laying the Foundation A Report of the First Year of the Blue Ribbon Panel on National Telecommunications Policy Kanis H 1993 Operation of controls on consumer products by physically impaired users Human Factors 35 2 305 328
25. AMPLE Provide adjustable volume controls on answering machines and telephones REFERENCE EIA 1994 Haigh 1993 Voice characteristics Either a male or female voice is acceptable In most applications voice style should be either friendly or neutral except for serious situations in which a reserved style is preferred COMMENT Provide an attention getting sound or words before audio presentation COMMENT Provide an auto repeat function or a means to repeat auditory messages REFERENCE Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Audio output redirection Devices with audio output should have jacks so that output may be redirected to alternate sources such as external speakers EXAMPLE Devices such as answering machines should have speaker jacks that allow redirection of output to facilitate use of these devices by hearing impaired individuals REFERENCE EIA 1994 111 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 4 0 Documentation Documentation is an important part of any product This section covers documentation guidelines including those related to written user manuals on line help on line error messages or labels associated with controls and or displays Consumers rely on documentation to help solve any problems they might have when working with the product and to give them the information they need to use the product Time spent writing and revising documentation
26. B is undesirable REFERENCE EIA 1994 Cushman and Rosenberg 1991 Frequency range for warning signals The recommended range for the energy of warning signals is between the frequencies of 400 HZ and 1500 Hz COMMENT Warbling undulating tonal signals should be between 500 Hz to 1000 Hz REFERENCE Cushman and Rosenberg 1991 Signal pattern for warning signals Use harmonic variation to signal urgency or warning to users of a large range of hearing capabilities COMMENT The alerting effectiveness of a warning can be increased by increasing intensity volume by modulating the amplitude or changing the frequency to make the pitch rise and fall COMMENT A rising pitch contour communicates a greater sense of urgency than a falling pitch contour COMMENT The shorter the time between pulses and the more irregular pattern of pulses provides a more effective warning than a regular pattern REFERENCE Cushman and Rosenberg 1991 110 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 3 4 3 4 1 3 4 3 3 4 4 3 4 5 Auditory Displays Synthesized or Recorded Speech and Music 3 4 3 4 5 Synthesized or Recorded Speech and Music Complexity Verbal messages are superior to nonverbal auditory signals for complex messages REFERENCE Wright and Barlow 1995 Adjustable volume and speed Speech or coded tones should have adjustable volume control and speed or be slow by default EX
27. COMMENT Many individuals with visual impairments can read with the assistance of magnifiers bright lighting and glare reducers REFERENCE Haigh 1993 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 2 4 7 Refresh Rate Avoid screen refresh flicker or flashing and avoid frequencies which are most likely to trigger seizure activity 10 25 Hz REFERENCE Vanderheiden and Vanderheiden 1991 94 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 5 2 5 1 Displays Graphics Icons 2 5 2 5 2 Graphics and Icons In addition to the importance of legibility and visibility of displays designers should ensure that the messages conveyed by the display are easy to understand Symbols or icons are an effective means to transmit information to the user Symbols have been used for labels public information and traffic signs for some time More recently symbols as icons have become an important part of human computer interaction and are used extensively in computer displays Overall graphics and icons serve a number of purposes They help to reduce display density by conveying as one symbol information that would otherwise require a number of words Graphics in particular also can be used to show component relations or to display complex relationships They also provide a good presentation means for dynamic data but should not be used for exact numeral readings Icons can facilitate d
28. Design of Consumer Electronics 5 Functional Limitations 5 FUNCTIONAL LIMITATIONS This section describes each of the five different functional limitation types that are represented by these guidelines Designers are encouraged to read this section in order to understand the functional limitations of a very large proportion of the American population Mobility and Dexterity Limitations Mobility and dexterity limitations account for the highest percentage of functional limitations The greatest contributor to mobility and dexterity limitations is arthritis with 31 6 million people in the U S suffering from rheumatic diseases and 900 000 new cases of arthritis each year Cerebral palsy also affects a large percentage of the population more than 700 000 children and adults in the U S suffer from cerebral palsy There are 150 000 to 175 000 people in the U S with spinal cord injuries with projected increases of 7 000 8 000 a year Other accidents or illnesses that cause mobility and dexterity limitations include head injury stroke amputations Parkinson s Disease Multiple Sclerosis ALS Lou Gehrig s Disease and Muscular Dystrophy Individuals with these types of disabilities face a wide variety of functional limitations Problems include poor muscle control weakness and fatigue difficulty walking talking seeing speaking sensing and grasping Individuals have difficulty reaching things and doing complex or compound manipulat
29. FERENCE Honeywell Inc 1992 Variety A variety of complex tones sounds and speech should be used for displaying different types of information REFERENCE Wright and Barlow 1995 Auditory coding If sounds are used as codes the maximum number of auditory signals that can be discriminated is 4 different frequencies 3 different loudness levels 2 different sound durations or 6 different combinations of frequency and loudness The number of sounds with different meanings should be minimized for critical information REFERENCE Cushman and Rosenberg 1991 108 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Auditory Displays Tones and Beeps 3 2 5 3 2 5 Tactile aids Provide a tactile indication of auditory information for effective communication with hearing impaired users COMMENT If a built in tactile indication of auditory information cannot be provided facilitate the connection or use of attached tactile aids REFERENCE Vanderheiden and Vanderheiden 1991 109 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 3 3 3 3 1 3 3 2 3 3 3 Auditory Displays Warning Signals 3 3 3 3 3 Warning Signals Sound level of warning signals An auditory signal that exceeds normal sound level by 15 dB or any maximum sound level with a duration of 30 sec by 5 dB is desirable EXCEPTION An auditory signal that exceeds normal sound levels by 120 d
30. Industry Consumer Researcher Work Group of the Consumer Product Design Guidelines Project Wilson J R and Corlett E N eds 1990 Evaluation of Human Work A practical ergonomics methodology London Taylor amp Francis Ltd Woodson W 1981 Human Factors Design Handbook New York McGraw Hill 55 Resource Guide for Accessible Design of Consumer Electronics 9 References Wright M C amp Barlow S T 1995 Resource Document for the Design of Electronic Instrument Approach Procedure Displays Report No DOT FAA RD 95 2 Washington DC U S Department of Transportation Federal Aviation Administration 56 Part 3 Design Guideline Reference 57 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 10 DESIGN GUIDELINES 10 CONTROLS Controls are used to interact with all consumer electronic equipment They are used to manipulate settings e g volume rotary knob on a stereo interact with displays e g entering the time on a digital alarm clock and enter information e g typing on a computer keyboard Before designing controls for any product the following items should be considered e task characteristics what is the user going to be doing with the product e requirements for speed of operation will the user be required to operate this product under emergency conditions e adjustment accuracy is fine tuning necessary or will only gross adjus
31. PLE A legend page or content sensitive help help for a selected symbol should be available with textual descriptions for each symbol REFERENCE Wright and Barlow 1995 96 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 6 2 6 1 2 6 2 Displays Color 2 6 2 6 2 Color Amount of Color Use color conservatively With regard to the number of different colors in the display the general rule is less is better for all users COMMENT The number of colors appropriate for use on a display can depend on the application Hundreds of shades can be used for imaging and solids modeling in computer aided design However for simple applications 10 different colors may cause problems COMMENT If color is used to convey meaning as in color coding employing five colors within a display is the maximum number of colors to be used for high accuracy Identification errors occur when any number over five is used RELATED GUIDELINES 1 2 6 2 6 3 REFERENCE Salvendy 1987 Vanderheiden and Vanderheiden 1991 Color Differentiation Consider that those with color blindness may have difficulty differentiating between certain color pairs with information that is color coded or where color pairs are chosen which result in poor figure ground contrast COMMENT Color with appropriate contrast between message and background enhances legibility for many people with low vision Red characters tend to wash
32. Resource Guide for Accessible Design of Consumer Electronics DRAFT September 9 1996 Submitted to EIA EIF Committee on Product Accessibility A Joint Venture of the Electronic Industries Association and the Electronic Industries Foundation Washington DC 20006 Submitted by Monterey Technologies Inc 1143 G Executive Circle Cary NC 27511 CONTENTS Part 1 Executives Guide to Accessible Design 1 Introduction 4 2 Trends Driving Accessible Design 6 3 Benefits 7 Part 2 Designers Guide to Accessible Design 4 General Design Principles 12 5 Functional Limitations 16 6 Where Should I Go From Here 22 7 Design Evaluation and Checklist 24 1 0 Controls 27 2 0 Visual Displays 35 3 0 Auditory Displays 39 4 0 Documentation 41 8 Accessible Design Example 43 9 References 52 Part 3 Design Guideline Reference 10 Design Guidelines 56 1 0 Controls 56 2 0 Visual Displays 84 3 0 Auditory Displays 103 4 0 Documentation 111 5 0 Accessories and Modifications 118 ACKNOWLEDGEMENT Since the mid 1980s the Electronic Industries Alliance its Assistive Devices Division then part of EIA s Consumer Electronics Group and the Electronic Industries Foundation have been working together to address linking product design with the needs of persons with functional limitations As part of this effort E A and the Foundation co sponsored the establishment in 1990 of a formal committee to draft guidelines for the design of accessible con
33. abeled items are interpreted EXAMPLE The sequence of numbers 513 555 6161 could be understood as a telephone number if it appears in a telephone directory but may be unidentifiable if it appears in an unformatted display REFERENCE Bailey 1989 4 2 9 Meaningfulness Find a label that is meaningful to the user or use complete words as the label COMMENT Do not use any labels that appear to be unfamiliar to the user population Labels should be tested for meaningfulness to ensure that the correct message is being communicated to the user COMMENT If an abbreviation is to be used as a label then ensure that it is meaningful to user Consult a dictionary for a list of standard abbreviations for common words REFERENCE Bailey 1989 4 2 10 Distinctiveness and Consistency Consistent concise and distinct labels that adequately describe the associated object and field should be used COMMENT Eliminate irrelevant information and decoration COMMENT If data entry fields are used the labels for the fields should be distinctive in appearance and in wording from the data in the fields COMMENT Adopt a consistent format for relating labels with data entries when entry fields are distributed across a display COMMENT The labels should be designed such that they appear to the left of the field or above the field REFERENCE Bailey 1989 Wright and Barlow 1995 4 2 11 Appearance See Section 2 4 Alphanumeric Displays for speci
34. activation as the key is held down Also a depressed key should indicate on and an associated display mechanism should be provided to indicate the state of the controls COMMENT For mobility impaired users simultaneous key presses may be difficult and an auto repeat function may create problems for users who do not have much finger dexterity REFERENCE Cushman and Rosenberg 1991 Honeywell Inc 1992 1 6 1 Feedback Travel distance For adequate feedback a positive click should be felt to indicate activation and minimal travel distance should be e 0 05 inches for small keys e 0 25 inches for larger keys REFERENCE Honeywell Inc 1992 1 6 2 Separation There should be a minimum of 0 25 inches between keys measured at the tops of the keys REFERENCE Cushman and Rosenberg 1991 Honeywell Inc 1992 1 6 3 Size The key should be from 0 375 to 0 75 inches in diameter either square or rectangular REFERENCE Honeywell Inc 1992 1 6 4 Force The force required to activate keys should be e 1 to 10 oz for alphanumeric keys e 3 5 to 15 oz for numeric keys COMMENT Smaller keys should use forces in the lower range and larger keys should use forces in the higher range REFERENCE Cushman and Rosenberg 1991 Honeywell Inc 1992 1 6 5 Reference keys In keyboards or keypads provide tactile markers as reference points on important keys for individuals with visual disabilities EXAMPLE Raised dots on normal index fing
35. age 16 and 100 cm at age 60 Decrease in contrast sensitivity from age 20 to age 80 there is a progressive decrease in the ability to distinguish between light and dark with the main decline beginning around age 40 or 50 Increased sensitivity to glare the vision of individuals over 40 is more impaired by glare than is the vision of younger individuals Longer dark adaptation times it takes longer for an older person to become accustomed to seeing in a dark environment after coming from a light environment Decline of color vision and discrimination color vision and discrimination improves until age 30 then gradually declines from the ages of 30 40 Decline of binocular depth perception stereopsis the ability to perceive depth by using both eyes remains constant until age 40 then declines until age 70 Perceptual and Cognitive Limitations There are a wide range of perceptual and cognitive impairments that limit individuals ability to use consumer electronics Cognitive impairments vary from severe retardation to memory problems to the impairment of specific cognitive functions such as language Three percent of 17 Honeywell 1992 S Haigh 1993 20 Resource Guide for Accessible Design of Consumer Electronics 5 Functional Limitations Americans are mentally retarded Of these 80 85 have mild retardation 10 have moderate retardation and 5 10 have severe retardation Individuals with mild retardatio
36. age loading simple obvious sequences and cued sequences These individuals have difficulty hearing and speaking using written or electronic documentation using automated systems and using visual displays for example telecommunications systems and Automated Teller Machines Methods of improving designs to make them more accessible to this population include the use of voice prompts increased size of print simple fonts high contrast labels with icons or graphics and progress displays Another category of cognitive impairments with different implications for design is seizure disorders Between 0 5 and 1 5 of the population suffer from chronic recurring seizures The affect on individuals can vary from momentary loss of attention to severe loss of motor control and awareness grand mal seizures Except during the short period of the seizures cognitive 1 Vanderheiden amp Vanderheiden 1991 Vanderheiden amp Vanderheiden 1991 Vanderheiden amp Vanderheiden 1991 22 Kaplan DeWitt amp Steyaert 1990 21 Resource Guide for Accessible Design of Consumer Electronics 5 Functional Limitations function is normal unless they suffer from other impairments Of importance however is that some seizure disorders may be triggered by rapidly flashing lights For individuals with this type of disorder seizures may be triggered by displays or other types of lighting that flash or update at arate in the 10 25 Hz range
37. ages Pf f foo 3 4 2 Adjustable volume and speed Pf f foo Adjustable volume control and speed Pf f foo 3 4 3 Voice characteristics Pf f foo Friendly or neutral voice style EE ee Attention getting noise precedes voice ODS SE Audio output redirection C E ____ __ Provides audio output jacks et a 42 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist s satisfactory m marginal u unsatisfactory 4 0 Documentation U Guidelines S M Comments 41 Gener o O General 4 1 1 Margins and Character Spacing Flush left and ragged right margins No proportional spacing 4 1 2 4 1 3 Underlining Discernible space between line and letters 4 1 4 Character strokes Uses solid lines to form character strokes Avoids characters with breaks in strokes 4 1 5 Hyphenation No hyphenation 4 1 6 Product documentation format Loose bindings so columns lay flat 4 1 7 Character contrast Dark characters on light background Off white vellum or eggshell for background 4 1 8 Spacing with Large Print Avoids unneeded space between characters Affirmative statements Uses mostly active sentences in expression Avoids passive or negative statements Labeling Tactile Labels Text and or icons raised 1 32 Uses upper case sans serif style text 4 2 2 Dynamic Labels ATT ae fcc TP dynamic labels for use by blind 4 2 3 Pictograms e ED information ee Pe 4 2 4 Has a r
38. aille labels An example of redundant coding of information is using both button shape and color to characterize different controls or different features of a control 4 Make Functions Conspicuous Visibility is one of the most important principles of interface design The principle of visibility means that all features functions actions and controls should be immediately apparent to the user Rather than use the term visibility which implies the sense of sight it is suggested that all features functions actions and controls be conspicuous to users with varying functional limitations Functions should be immediately apparent whether it be through sight hearing or touch The actions that are required to initiate the functions and the expected result of the function should be apparent to the user Ideally functions should be apparent through more than one sense Inconspicuous functions include buttons that are placed to the side or the back of a product Often combinations of button presses or multiple functions assigned to a single control make functions inconspicuous Examples of functions that are conspicuous to users are controls that are placed on the front of a product with labels or icons to indicate the function These controls are conspicuous to a wider range of users if the labels are presented in raised letters or if the controls have Braille labels as well In situations where all functions cannot be immediately
39. am products the cost will be shared among a larger market than if manufacturers must create special products for the functionally limited This will make it much more likely that the functionally limited will choose this type of product rather than a specialized product The design changes will also increase the marketability of the product to the general population who may be willing to pay a little extra for features such as adjustable volume controls or backlighting The cost of incorporating accessible design into mainstream products is minor compared to the cost of retrofitting products at a later date With the trends toward accessibility in legislation described above there is a possibility that legislation will require product modifications to make them more accessible especially for products used in public places While this cost may not be 11 Resource Guide for Accessible Design of Consumer Electronics 3 Benefits distributed directly to the manufacturer a manufacturer that has already considered accessibility in his design will have a decided advantage over a manufacturer that has not Why make the changes if we re not legally required to In many ways accessible design is legally required While manufacturers may not be required to create products that are accessible many of the customers that will purchase the products are required to offer services that are accessible The ADA requires that employers offer accommoda
40. anding positions special consideration should be taken in testing the display for those individuals in wheelchairs COMMENT A normal viewing angle for a seated operator is about 15 degrees below the horizontal COMMENT The preferred line of sight and its dynamic range vary according to task and user requirements Individuals working at a desk often assume angles of up to 60 degrees below horizontal For most applications the normal viewing angle can assume just about any value between 0 and 50 degrees below horizontal REFERENCE Salvendy 1987 Printouts Printed output should be placed within easy reach of those who are in wheelchairs COMMENT If necessary facilitate manipulations of printouts from display devices by providing reaching and grasping aids REFERENCE Vanderheiden and Vanderheiden 1991 89 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 3 2 3 1 Displays Alphanumeric Displays 2 3 2 3 2 Alphanumeric Displays Some of the guidelines in this section refer to a visual angle size in terms of minutes of arc Visual angle is the size an object subtends on the eye and is dependent on the size of the object being viewed and the distance of the viewer from the object Visual angle in minutes of arc can be obtained from the following formula Visual angle min of arc 57 3 60 L L the size of the object and D D the distance from the eye to the object Size The pr
41. ange from 16 to 20 point print size Height to width ratio 1 0 7 1 0 9 ff Stroke height to width ratio 12 1 3 751 oo 4 2 5 Characters TEP Uses a simple character design Pech ah Embossed characters have sans serif type Pf f foo 4 2 gt gt X 43 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines Spacin 1 1 2 times capital letter height 4 2 7 Contrast o 4 2 8 Identification Labeled completely and clearly 4 2 9 Meaningfulness Labels are meaningful and familiar to users Labels use complete words or standard abbreviations 4 2 10 S M BE eS Pet Zia le nz Eiai ee ae l Em a ace aes m Ro m See Guidelines for sections 2 3 and 2 4 on rE size spacing brightness and contrast for labels Ea E l E E E l E P E ne ai Pals za ee as fea ae T 4 On line Documentation Provides on line user assistance Access to help facilities on each screen 4 4 3 2 lence 43 3 4 3 4 2 2 3 3 3 3 3 Gives definitions of abbreviations on line Phrased politely and in helpful manner Same message given consistently for same error 44 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example 8 ACCESSIBLE DESIGN EXAMPLE This section is provided as an example of the application of the road map checklist and guidelines in the evaluation of a consumer ele
42. atibility The grouping should coincide with user s expectations In addition controls should be grouped so that they aid in determining which control affects which display which control affects which equipment component and which equipment component is described by each display EXAMPLE All of the controls that affect the CD player on a portable CD Cassette Radio stereo system are grouped around the CD player REFERENCE Bailey 1989 Grouping by function and sequence When possible controls should be grouped by their function and in the sequence that they will be used EXAMPLE All of the CD controls are grouped together all of the cassette controls are grouped together all of the sound controls are grouped together etc REFERENCE Bailey 1989 64 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Arrangement_1 4 4 1 4 5 1 4 4 Direction of movement The direction of movement of a control should be considered in relation to e the location and orientation of the user relative to the control e the position of the display relative to the control and the nature and direction of the display s response e the change resulting from the control movement either in terms of motion of moving components landing gear automobile wheels or in terms of some dimensional quantity volume brightness COMMENT The direction of movement of controls should be horizontal rather than vertica
43. back Auditory feedback when activated y No added auditory feedback but proprioceptive feedback and natural sound is okay Visual feedback when activated CAEN ae 49 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example Guidelines S 1 5 4 Separation 0 5 to 2 0 inches apart for finger operation At least 6 inches for palm activation 1 5 5 Size 0 5 to 1 0 diameter for finger activation s satisfactory M marginal U unsatisfactory 2 0 Visual Displays Guidelines S M U Comments 1 General 2 1 1 Conspicuity ft ft Display attracts attention He A 3 Labels obstructed by rotary controls Display is easily visible ESNE 2 1 2 Emphasis Fa a E Important words emphasized a e ee Clock display okay radio display is too small 2 1 3 Legibility Enhanced contrast ratio Easy to read fonts Large fonts 16 point minimum 2 1 4 Intelligibility Clarity of message and relevant action Avoids unknown acronyms or abbreviations Not easily visible at angles 2 1 6 Size le Proper for type and amount of information V Appropriate for expected viewing distance 2 1 7 Maintainability ae Materials resist aging and wear 2 1 8 Standardization re Uses industry recognized words symbols Alphanumeric Displays 3 ize 2 3 1 Characters as large as practical 20 to 22 minutes of arc visual angle Printed text at 16 to 20 point print size 2 3
44. character height or 1 min arc whichever is greater COMMENT Neither the height nor width of a character should vary by more than 10 regardless of its display location within the image area REFERENCE Cushman and Rosenberg 1991 EIA 1993 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Wright and Barlow 1995 90 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 3 3 2 3 4 2 3 5 Displays Alphanumeric Displays 2 3 3 2 3 5 Spacing Appropriate letter word and line spacing will improve legibility of printed information e Between character spacing should be the width of one stroke or one pixel whichever is greater e Between word spacing should be the width of one character For proportional typefaces the width of the capital letter N should be used for spacing e Between line spacing should be the width of two strokes or two pixels whichever is greater Preferred spacing is from one half character to full character height Between line spacing is measured from the lowest descender on one line to the highest uppercase letter on the next line COMMENT Make sure that the space between lines and the distance between messages is sufficient that the letters and messages stand out distinctly from each other REFERENCE Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Typeface Keep letters and symbols on visual output as simple as possible Use a sans seri
45. cklist Guidelines Standardization Color coding is standardized consistent 1 2 6 Colored lights and surfaces No more than 3 different colored lights No more than 9 different colored surfaces 1 2 7 Choice of colors Colors appropriate for vision capabilities Red green white or blue used for rapid identification 1 2 8 Location coding Switches separated by at least 2 5 inches vertically Switches separated by at least 4 inches horizontally 1 2 9 Pictorial symbols No more than 10 different symbols Separation Sufficient distance for adequate grasping 1 3 1 Pushbuttons i Separation is 1 2 width of control Small controls are 3 4 2 apart 1 3 2 Rotary knobs Separation is 1 2 apart 1 3 3 Toggle switches Separation is 1 2 apart 1 3 4 Foot controls Separation is 2 4 apart for pedals Separation is double that of hand controls SS A The most frequently used controls are PP Pp positioned for easy access 4 2 Grouping for compatability ee Coincides with user expectations Pf fo Indicates control display relationship Pf ft fo O OE 4 3 Grouping by function and sequence S Controls with similar or related functions a grouped together wale e Grouped according to order of use 30 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines 1 4 4 Direction of movement Considers location and orientation of user Compatible with posi
46. ctronics product The product chosen for the evaluation is a clock radio First the original product will be described Second the steps of the evaluation will be covered Finally recommendations for changes and a description of the updated product will be provided Functional Description of Original Clock Radio The original clock radio has 12 controls two rotary knobs and two slide switches on the right side one rotary knob one slide switch and two pushbuttons on the left side three pushbuttons on the top and one slide switch on the bottom of the radio The radio has two displays a clock display on the left and an AM FM radio display with a sliding marker on the right The clock display is an LED display with segmented numbers The radio display has fixed labels and a scale that are sidelit A graphic of the radio is shown below Clock Radio yot 10 ALARM AM pute m AM qoe o 5460 70 80 100 120 140 160 M gOC O L l 88 92 98 102 103 108 Left Side Bottom Ta E Q TIME SET DISPLAY FAST SLOW T S26 DIM BRIGHT zZ a TIME SET LOCK The clock radio has several functions It functions as a radio a clock a buzzer alarm clock and a radio alarm clock The radio function is fairly straightforward Using the SELECTOR slide 45 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example sw
47. d This is helpful for users with mobility restrictions Personal Access Devices A personal access device is a device that a user can utilize to interact with a product using a bi directional infrared wireless data link Personal access devices may take different forms for different individuals based on their needs When a total access port TAP is connected to a product it serves as the interface between the product and the user s personal access device Products that incorporate TAPs or allow the connection of TAPs will accommodate the use of various personal access devices by disabled individuals This section of the document provides a few guidelines for incorporating accessories or accommodating modifications Many of the guidelines are general benefiting all users but several have implications for specific groups of disabled users 120 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 5 1 5 2 5 3 5 4 5 5 5 6 Accessories and Modifications 5 1 5 6 Telephone Handsets The following are recommendations for designing telephone handsets e Handsets must be hearing aid compatible e Having handsets compatible with in line auxiliary amplifiers is desirable e Having handsets compatible with portable auxiliary amplifiers is desirable e Use of G or K Style handsets is desirable for use with TDD acoustic couplers deaf REFERENCE EIA 1994 Eye Control Devices Manufactu
48. delines S M U Comments 18 1 8 1 Active surfaces E Active surfaces detectable tactually EEn 1 8 2 Feedback Se Ae auditory and visual feedback 1 8 3 Separation SY At least 0 25 between touch sensitive areas 1 8 4 Size Minimum 3 4 square for touch areas 1 eae 5 Accidental Activation 155 tas activation by heat or electricity 1 8 6 Critical Functions O e an T E A validation or Teont 1 9 1 Shape Operation PE Two faces of switch atobtuseangle fo Upper right or away part of switch turns Pik on starts engages 1 9 2 Feedback ee re Adequate tactile auditory and or visual feedback 1 9 3 Angular Travel ee Around 30 degrees of angular travel EEn Depressed face of switch backlighted EEn 1 9 4 Separation TE PP Minimum of 0 75 inches apart ee 195 Sze o T Between 0 5 and 2 5 inches in length Se PS O OE Between 0 25 and 1 5 inches in width OPP PS O OE 1 9 6 Force a a a 10 40 oz of force to activate LCD S 1 10 Rotary controls 3 12 discrete positions S Fixed scales and moving pointers S Scale not obscured by controluse S 1 10 1 Mounting rotary controls EE No gang mountins TEP 1 10 2 Continuous rotary controis S Coarse setting 180 rotation to 6 of ito linear scale motion Fine setting 180 rotation to 1 2 of is linear scale motion 33 Resource Guide for Accessible Design of Consumer Electronics 1 10 3 1 10 4 1 10 5 1 10
49. dundantly through a visual display channel More importantly the auditory channel provides another means of communication for the visually impaired Used in conjunction with a visual display channel auditory channel displays can provide an additional communication means that can increase the probability that an important message will be received The auditory channel is quite effective for conveying different types of system information to an operator The implementation of an auditory display in such applications as alarm and warning signals on flight decks of passenger aircraft has lead to increased efficiency and safety of a system Auditory displays are also used for speech communication in the form of either synthesized or recorded speech When deciding what type of auditory information to use e g tones beeps or recorded speech one should choose a sound for an auditory display that is in distinct contrast to the sound environment For example voice indicators should be used for non voice environments and non voice indicators should be used for voice environments This section of the document provides a number of guidelines for designing auditory displays The special needs of the physically and cognitively impaired will be considered and specific suggestions for designing features with respect to this population will be considered The following is a listing of the features and design issues that will be addressed in this section 3 1
50. e equipment e Orient toggle switches rocker switches levers sliding controls etc so that the direction of control movement is perpendicular to the expected direction of hand movement in most cases the switches should be vertically oriented COMMENT Some physically disabled users may be more likely to accidentally activate a control because they have poor motor control However designers should take care to ensure that the design of controls to prevent accidental activation does not hinder intentional activation of the control If accidental activation of the control is not serious or is easily reversed then it is more important that the control be relatively easy to activate REFERENCE Cushman and Rosenberg 1991 Salvendy 1987 Labeling In general labels should be placed horizontally above the control to facilitate reading The label should be visible to the user before they reach for the control and the label should be descriptive enough to tell what is being controlled e g gear position brightness level function key number RELATED GUIDELINES See section 4 2 in Documentation for more guidelines on labeling REFERENCE Bailey 1989 Sanders and McCormick 1987 60 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 2 1 2 1 1 2 2 1 2 3 1 2 4 Controls Coding 1 2 1 2 4 Coding In general when coding controls redundant methods of coding should be used EXAMPLE A
51. e frequency of the alarm and the range of the volume control 47 Resource Guide for Accessible Design of Consumer Electronics 1 0 Controls G General Selection 1 1 1 Proper control for task 1 1 2 Shape size and texture Easy to hold and grip Location Easy to access 1 1 4 Orientation i Vertical for precision Horizontal for power 1 1 5 Force required ia Minimal strength required Short duration of operation 1 1 6 Simultaneous manipulation lea No simultaneous motions required 1 1 7 Preventing accidental activation n Action can be reversed If activation is serious prevention methods used Labeling Placed horizontally Visible and descriptive Coding Redundant methods used 1 3 a Sufficient distance for adequate grasping y Shape Discriminable by touch Associated by function No more than five different shapes Separation 1 3 Separation is 1 2 width of control Small controls are 3 4 2 apart 3 2 Rotary knobs Separation is 1 2 apart 3 1 Pushbuttons 8 Accessible Design Example s satisfactory M marginal U unsatisfactory S MU SEE vf fo iE a Pe y Check dimensions for specific types of controls ATT _ W Slide switch on bottom of product N O a A E24 a ee a V Check for slide switches E i ar ae V Setting alarm S H E 48 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example Guidelines S M U Comment
52. e located and what it will be used for Sections 1 5 through 1 17 provide detailed guidelines on various different types of controls In general pushbuttons and slide switches are desirable controls to use for visually and physically impaired users Push pull switches are not recommended COMMENT With slide switches relative position can be detected through proprioceptive feedback of switch movement REFERENCE EIA 1994 Shape size and texture The shape of the control should be easy to hold so that it fits the hand There should also be a texture to the control so that it can be gripped and held onto The control should not be so small that it is buried and it should not be so large that it cannot be gripped COMMENT When designing for the visually impaired shape coding and increasing the size of labels should be considered REFERENCE Cushman and Rosenberg 1991 Haigh 1993 Location In general controls should be located in an area that will allow the user direct access to it EXAMPLE Controls located on the side or back of consumer electronics are difficult to access for the physically handicapped REFERENCE Kanis 1993 Orientation If precision is needed in operating the control s it should be oriented vertically if strength is need it should be oriented horizontally REFERENCE Kanis 1993 Force required Users should not be required to hold a control down for a period of time except when overruled by safety req
53. e needs of both mainstream and disabled users This document is separated into three parts The first part is directed to electronic industries executives It describes the initiative of the Electronic Industries Association to encourage the design of accessible products and discusses the benefits of accessible design It describes trends in the industry that are encouraging and in some cases trends that are legislating accessible design The second and third parts of the document are directed toward product designers Part two provides useful background information and a description of how to use the design guidelines provided in this document Chapter 4 lists eight design principles that will help designers create products that are more accessible Chapter 5 provides a description of the functional limitations addressed in this document so that designers are more aware of their target audience In Chapter 6 a road map is presented to help designers easily find specific checklist items or guidelines that apply to their product Chapter 7 describes how to evaluate a product and provides a summary checklist that designers should use in evaluating their design Chapter 8 provides an example application of the roadmap checklist and design guidelines to improve the accessibility of a consumer electronic product Chapter 9 lists the references used in the creation of this document and the design guidelines Part 3 of the document contains specific gu
54. e subjects are to the intended user population the more reliable the results will be Subjects are required to perform a set of tasks that are developed based on the expected function of the product A list of functions should be obtained and tasks can be developed from that list There should be enough tasks to fully evaluate every aspect of the product The tasks should be detailed enough to obtain the necessary information but should be short enough to allow the subject to complete them during the allotted test time Both objective and subjective information are collected in a usability test The objective information can include items such as errors on tasks time to complete tasks and successful completion Not being able to finish a task within the previously set time limit making a large number of errors or not completing the task successfully can all be indicators that the display control or function may need to be reevaluated and redesigned Subjective information can 26 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist include user preferences on appearance and function which might be important from a marketing aspect A two person test team usually conducts the usability test That team is made up of a test administrator and a test technician The administrator interacts with the test subject informs them of what they should do explains the testing procedure answers any q
55. ecommended brightness contrast ratio should also be maintained Color contrast may be difficult to distinguish for older individuals or individuals with color blindness REFERENCE Cushman and Rosenberg 1991 EIA 1994 Haigh 1993 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Contrast Adjustment Provide contrast adjustment to accommodate those of all levels of visual capability EXAMPLE Increase contrast on LCD displays by allowing the user to adjust viewing angle REFERENCE Vanderheiden and Vanderheiden 1991 Brightness Adjustment In order to accommodate a wide range of visual capabilities provide adequate brightness adjustment REFERENCE Bailey 1989 Haigh 1993 Brightness Coding If brightness is used as a code to indicate some type of meaning use only two brightness levels normal brightness and enhanced brightness REFERENCE Brown 1988 Cushman and Rosenberg 1991 93 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Brightness Contrast and Refresh Rate 2 4 5 2 4 7 2 4 5 Illumination The amount of light illumination on an alphanumeric display should not be significantly exceeded by the ambient light or bright lighting source behind or in front of the information on the display REFERENCE EIA 1994 Cushman and Rosenberg 1991 2 4 6 Reduction of Glare Use non reflective surfaces to minimize glare EXAMPLE Use filtering devices on screens
56. eferred height of letters and numerals depends upon the viewing distance ambient illumination and the importance of the text Make letters and symbols on visual output as large as possible and practical to take into account those with low vision COMMENT In order to accommodate users with low vision a recommended height for alphanumeric characters is 20 to 22 min of arc visual angle subtended from the eye A reading distance of no less that 12 in should be used to determine visual angle COMMENT Alphanumeric characters must be large enough to be clearly read from the maximum anticipated viewing distance COMMENT For printed material a range of 16 to 20 point print size is recommended COMMENT Test the size of type to be used in the display with a range of the user population including those with visual and physical impairments under all possible levels of illumination viewing distance and viewing angle REFERENCE Honeywell Inc 1992 Salvendy 1987 Vanderheiden and Vanderheiden 1991 2 3 2 Height to Width Ratios Readability is improved when characters are simple and have good height to width ratio and stroke width with no openness within the characters Some recommended height to width ratios and stroke widths are e Height to width ratio of characters in fixed column presentation should be 1 0 7 to 1 0 9 e Height to width ratio for proportionally spaced characters should be 1 0 5 to 1 1 e Stroke width should be 1 12
57. elecommunications system to be fully accessible to individuals with hearing and speech disabilities Section 508 of the Rehabilitation Act as amended in 1991 and 1992 requires that the General Services Administration develop and adopt guidelines to ensure federal employees with disabilities can use electronic office equipment and information technologies leased or purchased with or without special peripherals The most recent legislation influencing electronic product design is the Telecommunications Act of 1996 signed by the President in February 1996 According to this Act the Federal Communications Commission FCC must issue new regulations requiring increased use of closed t Kaplan amp DeWitt 1993 or 1994 Kaplan amp DeWitt 1993 or 1994 Resource Guide for Accessible Design of Consumer Electronics 2 Trends Driving Accessible Design captioning on video programming The FCC must also examine the use of video descriptions audio narration of video elements to ensure accessibility of programming to persons with visual impairments Manufacturers of customer premises equipment will be required to ensure that their equipment can be accessible to individuals with disabilities Guidelines will be developed by the Architectural and Transportation Barriers Compliance Board for access to customer premises equipment and telecommunications equipment A Telecommunications Access Advisory Committee TAAC has been formed to address these
58. ences should be short concise distinct affirmative and in the active voice This will improve the speed and accuracy of comprehension EXAMPLE The distinct wording will not is preferable to won t EXAMPLE The affirmative instruction Clear the screen before entering data is preferable to the negative instruction Do not enter data before clearing the screen REFERENCE Wright and Barlow 1995 92 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 4 2 4 1 2 4 2 2 4 3 2 4 4 Displays Brightness Contrast and Refresh Rate 2 4 2 4 4 Brightness Contrast and Refresh Rate Brightness Contrast The brightness or luminance of an object is the perception of the intensity of light reflected from that object Brightness contrast can be defined as the ratio of the luminance of an object of interest to its background Characters should contrast with their background either light characters on dark background or dark characters on light background A brightness contrast of between 6 1 and 15 1 is recommended COMMENT Higher brightness contrast ratios may help those with visual impairments COMMENT Local brightness contrast ratios e g between different active and inactive pixels on a display are as important as average brightness contrast and should be measured as well COMMENT Even if color contrast distinguishes an object from its background the minimum r
59. er discrimination RELATED GUIDELINES 4 2 4 REFERENCE EIA 1994 Hyphenation Hyphenation of words should be avoided whenever possible REFERENCE EIA 1994 Product documentation format Product documentation should be produced in loose bindings so columns can lay flat to keep focal length constant REFERENCE EIA 1994 113 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 4 1 7 4 1 9 Documentation General 4 1 7 4 1 9 Character contrast Black or otherwise dark characters on a light background are preferred for printed materials COMMENT Off white vellum or eggshell finish 11 19 degree gloss when tested with a 60 degree glossimeter is recommended for the background of printed material using dark characters This reduces reading problems caused by glare REFERENCE EIA 1994 Spacing with large print It is undesirable to provide unusual amounts of additional space between characters when they are displayed in large print Type font options provided by standard word processing software give the appropriate character spacing for character sizes selected REFERENCE EIA 1994 Affirmative statements A label or message can be expressed in an active passive or negative manner Active statements are generally easier to understand than passive or negative statements EXAMPLE Use the active sentence rather than the passive or negative sentence e The large lever controls the dep
60. er positions on a typewriter or keyboard or on the central number key usually 5 on a numeric keypad help individuals with low vision to locate desired keys Tactile reference markers are useful to anyone wishing to reference keys without looking at them e g for touch typing 69 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 7 1 7 1 1 7 2 1 7 3 Controls Membrane Keys 1 7 1 7 3 Membrane Keys Some things to avoid when using membrane keys are multiple finger simultaneous operations and auto repeat activation as the key is held down Also a depressed key should indicate on and an associated display mechanism should be provided to indicate the state of the controls COMMENT For mobility impaired users simultaneous key presses may be difficult and an auto repeat function may create problems for users who do not have much finger dexterity REFERENCE EIA 1994 Honeywell Inc 1992 Surface The surface of membrane keys should be easily differentiated tactually from the main surface of a product such as by a matte non slip surface a textured or raised dot or simple or by being raised or contained within a raised boundary Having the center of the button slightly dished is also recommended The edges should be raised above the surrounding panel surface and color coding and other visual demarcation of edges should be provided COMMENT It is important for visually impaired
61. er to increase vocabulary size without lowering recognition accuracy and processing time place constraints on what items can be said and in what order By doing so the system will be able to look at a limited set of items at any time based on the order instead of looking at all items at all times REFERENCE Sanders and McCormick 1987 84 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 17 5 1 17 6 1 17 7 1 17 8 Controls Auditory Input 1 17 5 1 17 8 Recognition vocabulary Avoid acoustically similar vocabulary items for the recognition vocabulary Try to use terminology for the recognition vocabulary that is familiar to the users or for speaker dependent systems let individuals choose their own words for the system functions to be controlled by speech REFERENCE Salvendy 1987 Training Provide training for speech recognition system users to improve the consistency of their pronunciation and microphone usage COMMENT Expect poor speech consistency from about 25 of the population at large Provide practice time with the system as part of user training COMMENT Practice time and training is essential for users with speech impediments REFERENCE Salvendy 1987 Environment For speaker dependent systems that are to be used in noise levels above 85 dB SPL or under high acceleration levels make provisions for the speaker to develop the template of words and or adaptive reco
62. f or simple typeface without excessive flourishes or deviations in stroke width Avoid using characters that are similar to one another COMMENT Only one or two different typefaces should be used for emphasis REFERENCE FIA 1994 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Case Use a combination of upper and lower case for maximum readability by users at many levels of visual capability COMMENT Conventional capital and lower case presentation of text should be used especially for long chunks of text Upper case presentation may be preferable for the display of a single character only Upper case is also commonly accepted to indicate that the information presented is an acronym rather than a stand alone word COMMENT Case should be consistent across text unless a different case such as all capitals is used for highlighting key information COMMENT If upper case is required consider enlarging the first letter of the word to enhance the legibility of the word REFERENCE Vanderheiden and Vanderheiden 1991 Wright and Barlow 1995 91 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 3 6 2 3 7 Displays Alphanumeric Displays 2 3 6 2 3 Abbreviations and Acronyms The use of abbreviations and acronyms should be avoided except where they are common and familiar COMMENT Avoid the use of hyphenations REFERENCE Wright and Barlow 1995 Sentence Style Sent
63. fic guidelines regarding the size spacing brightness and contrast of labels for a display 117 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 4 3 4 3 1 4 3 2 4 3 3 4 3 4 4 3 5 Documentation On Line Documentation 4 3 4 3 5 On line Documentation Extensive on line user assistance should be provided There should be access to a list of system capabilities and subsystems as well as HELP facilities for each screen REFERENCE Brown 1988 Content Create an on line documentation system that explains purposes of screens explains screen transactions describes input and output data fields and describes codes commands and messages used COMMENT Ensure that the on line documentation is a situation specific function Requesting on line help should not cause data loss REFERENCE Brown 1988 Abbreviations and definitions Provide an alphabetical list of abbreviations with their definitions on line REFERENCE Brown 1988 Length On line documentation should be as concise as possible Error messages should be brief but informative REFERENCE Brown 1988 Error messages List and explain all error messages in the on line documentation The content of error messages should be appropriate to the user s level of knowledge and should always state e what error has been detected e which input field contains the error e what corrective action to take REFERENCE Brown 1988
64. formation and where in the development cycle the product is any of these methods can be used Heuristic evaluations can be done on drawings non working prototypes working prototypes as well as the finished product Generally heuristic evaluations occur early on in the development cycle in order to provide designers with good and bad points about the product that can be emphasized or changed through the iterative design process Usability tests and walkthroughs can be done on working prototypes or finished products and should occur towards the end of the design process All other methods usually are conducted as follow up evaluations on the finished product This section will give a brief description of usability testing and heuristic evaluations Usability Testing Usability testing is a systematic way to evaluate a product using individuals who are similar to actual users By performing a usability test designers can determine what the exact problems are with the product The main goal of a usability test is to determine good and bad aspects of the product that can be emphasized or changed as part of an iterative design process The users that participate in this type of testing should be as representative of the intended user population as possible A user profile should be established to ensure a representative group It might be necessary to know user characteristics such as age ability levels physical limitations or occupation The closer th
65. g e prosthetics i e artificial hand or hook e glare reducers e orthotics e dynamic Braille displays e reachers e Braille overlays e single switch based artificial voice e eye gaze operated communication aids Accessories for Hearing keyboards Impairments e headsticks e hearing aids e telecommunication devices for the Accessories for Cognitive Language deaf TDDs Impairments hearing aid compatibility e cueing aids text telephones e memory aids e cued sequences Several of the large software and hardware companies have made efforts to make their computer systems more accessible There have been some modifications made that allow users with special input devices to use their systems The following are examples of modifications that have been made to make computers more accessible IBM Apple and Microsoft SerialKeys SerialKeys allow the user to plug in an alternate input device into the serial port of the standard personal computer This makes the input coming in from that port look like it s 119 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines coming directly from the standard keyboard or mouse This is helpful for users who need to use mouthsticks headsticks etc when using a computer to input information Apple MouseKeys MouseKeys are an extension of the operating system that allows a user to control the mouse pointer through the keys on the number pa
66. gn Guidelines Controls Rotary Controls 1 10 10 1 10 11 1 10 10 Size Rotary controls should be between e 0 625 and 3 0 inches high e 1 0 and 4 0 inches long e 1 0 inches wide e between 375 and 4 inches in diameter COMMENT Increasing the size may make it possible for impaired users to exert more force by using both hands REFERENCE EIA 1994 Honeywell Inc 1992 Kanis 1993 1 10 11 Force Rotary controls should require between 12 and 48 oz of force to activate REFERENCE EIA 1994 Honeywell Inc 1992 77 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 11 1 11 1 1 11 2 1 11 3 1 11 4 1 11 5 Controls Slide Switches 1 11 1 11 5 Slide Switches Discrete detented slide switches should not be used for more than two positions They are preferred where only one gross movement is possible For continuous slide switches static friction decreases sharply when the control starts to move and therefore depending upon the amount of friction provided gross control positions can be identified by feel The top of the slide switch should be serrated to develop friction with the finger and a spring return on the switch should be avoided Movement up away or right should increase the level of the associated function COMMENT Discrete detented slide switches require precision in placement of the finger and precision in movement which might be difficult for mobility i
67. gnition in the operational environment COMMENT Consider potential conflicts between speech messages intended for the user and other speech communication in the task environment REFERENCE Salvendy 1987 Feedback Provide feedback as to what has been recognized by the system and allow the user to correct any recognition errors REFERENCE Salvendy 1987 85 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 0 Visual Displays An important part of most any electronic equipment visual displays present and summarize information that the user needs Visual displays are the preferred means for communicating information in a variety of situations They are preferred when the information or message is long or complex or will be referred to at a later time Visual displays are the best method for communicating information that deals with spatial location They can also be quite useful when information must be conveyed to a user in a noisy environment There are a number of different general applications for visual displays First visual displays are often used to indicate status such as the paper out light on a printer On copiers the visual display identifies functions by labeling the different controls Visual displays such as illustrations in a user manual can also instruct the user The visual displays in automobiles can convey warnings to the driver such as low battery or oil Lastly visual dis
68. he bottom of the 46 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example radio are the most difficult to read because they are raised letters in the same color as the background Step 2 Using the Road Map Checklist and Guidelines For a more complete evaluation of the clock radio the road map checklist and guidelines provided in this document are used First the Road Map to Applicable Design Guidelines on pages 22 23 is referenced to find the checklist items and design guidelines items that are applicable to this product Stepping through the questions it is determined that several of the checklist items on controls including 1 1 through 1 4 for general issues and 1 5 1 10 and 1 11 for pushbuttons rotary controls and slide switches are applicable The visual display includes numbers and text but no symbols Checklist items 2 1 through 2 4 are applicable for visual displays Section 3 1 and 3 2 are applicable for the radio and alarm Finally section 4 2 will be covered for the labels After the applicable guidelines have been identified the checklist and design guidelines are used to identify problems and recommendations Some excerpts from the checklist evaluation are shown on the following pages Checklist items that were not applicable were left blank Although it is not covered in this review a complete analysis would also cover the auditory aspects of the clock radio including th
69. he general public for example via electronic kiosks also be accessible to people with disabilities This requirement is not restricted to removing architectural barriers for the mobility impaired rather it includes a the accessibility of information to individuals with sensory and cognitive impairments The ADA requires that employers provide reasonable accommodation to employees with disabilities Employers must make modifications or adjustments to the job application process modifications or adjustments to the work environment and modifications or adjustments that enable an employee with a disability to enjoy equal benefits and privileges of employment The ADA also requires that state and local governments take steps to ensure communications with applicants participants and members of the public with disabilities are as effective as communications with others A number of other federal regulations require consumer electronics be designed to include the disabled The Telecommunications for the Disabled Act of 1982 requires that all essential telephones be hearing aid compatible The Hearing Aid Compatibility Act of 1988 requires that all wireline telephones manufactured in the US or imported for use in the US after August 16 1989 be hearing aid compatible Cordless telephones also were required to be hearing aid compatible by August 16 1991 The Telecommunications Accessibility Enhancement Act of 1988 requires the Federal t
70. icators 2 7 2 7 4 Visual Indicators Visual indicators are an important part of the communication process between the user and the system Three major categories of such indicators are emergency indicators visual alerting signals and status indicators The following guidelines provide information regarding the effective design of these three types of indicators Visibility All indicators should have high visibility and be multi directional To be viewable by those with low vision emergency indicators should be visible from greater than 10 feet COMMENT Use large type size bold type face and a unique border to ensure that it attracts attention REFERENCE EIA 1994 Illumination Illumination of visual emergency indicators and status indicators should not be significantly exceeded by the ambient light surrounding a visual status indicator A brightness of greater than 216 foot lamberts is desirable to help those with low vision REFERENCE FIA 1994 Blink Coding Blink coding should be used sparingly for well defined special meanings such as alarms Blinking can be used in an adjacent field such as a blinking symbol prefix or a blinking box around the data to draw attention to the message COMMENT Do not use differing blink rates to represent difference categories of data Use only two levels blinking and not blinking of blink coding REFERENCE Brown 1988 Cushman and Rosenberg 1991 Blink Rates The recommended blink
71. ice indicators for non voice environments and non voice indicators for voice environments REFERENCE Haigh 1993 107 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 3 2 3 2 1 3 2 2 3 2 3 3 2 4 Auditory Displays Tones and Beeps 3 2 3 2 4 Tones and Beeps Tones or beeps are effective ways to indicate successful input of information They can be useful to tell a user that additional input is needed but consider that repetitive beeping can be intrusive to the task or annoying to the user Frequency Range Use sounds that have a strong mid low frequency components to accommodate those that are hearing impaired Recommended ranges vary from 500 3000 Hz to 300 750 Hz Use lower frequencies for alarms and urgent messages including telephone ringers Lower the frequency of products with high pitched output devices to help the less severely hearing impaired COMMENT Displays using the extremes of auditory dimensions should be avoided COMMENT Multiple frequencies of less than 1000 Hz are desirable for a telephone ringer REFERENCE EIA 1994 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Wright and Barlow 1995 Adjustable frequency Provide an adjustable frequency in order to serve the widest range of users COMMENT If an adjustable frequency is not possible be sure to use frequencies within the ranges discussed in the above guideline RELATED GUIDELINE 3 2 1 RE
72. ics 10 Design Guidelines 1 10 5 1 10 6 1 10 7 1 10 8 1 10 9 Controls Rotary Controls 1 10 5 1 10 9 Discrete detented controls For discrete detented rotary controls there should be 15 to 40 degrees of angular travel between detented positions 30 degrees is recommended REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Feedback Types of feedback preferred include e tactile allows the user to feel the button s activation e visual to help determine the control s setting e auditory an audible click at each position COMMENT For visually impaired users the auditory click will provide adequate feedback For hearing impaired users the indicator light will provide adequate feedback REFERENCE EIA 1994 Elastic resistance Elastic resistance should increase and then decrease as the control approaches the detent and it should snap into position REFERENCE EIA 1994 Settings When settings are selected sequentially stops should be provided at the beginning and end of the range of control REFERENCE EIA 1994 Separation There should be a minimum of 2 0 inches of separation between the rotary controls COMMENT The larger the separation between controls the easier it will be for mobility impaired users to activate the control REFERENCE EIA 1994 Honeywell Inc 1992 Sanders and McCormick 1987 76 Resource Guide for Accessible Design of Consumer Electronics 10 Desi
73. ide of the radio Increases accessibility of function Tightens the space on the left side More likely to incur accidental changing of time Identifying the buttons without looking will be easier rather than recessed Slight increase in cost but only for original tooling Change the slide switches to switches that slide more Operating the switches will be easier New switches smoothly Increase the distance between detents may be more expensive more space is required especially on the SELECTOR switch Change the function of the FAST and SLOW buttons Allows easier setting of the clock A minor to HOURS and MINUTES so that one button changes programming change the hour and the other button changes the minutes Bl peta ra gloria view the clock in minutes and seconds one function of the radio ee eee switch between alarm set time set and lock simultaneous motions bd o en a raised labels Increase the size of the labels Easier to read Requires more space 11 Increase the size of the radio labels Easier to read Requires more space reduces separation 12 Move all controls to a single surface on the front or Easier to read Can still be grouped in functional top perhaps angled down of the clock radio areas Requires more space in front Requires redesign of radio shape increased cost May make it more difficult to distinguish controls by position Move most frequently used controls volume Easier access of
74. idelines grouped by design element The guidelines are intended as a reference Designers should use Part 2 of the document to determine which guidelines pertain to their application The guidelines are based on current human factors and disability literature as well as current design practices Each guideline is stated and then followed by exceptions comments examples references to related guidelines and original source references In some cases specific quantitative information was not available or was too specific to be practically included considering the many different consumer electronics applications this document is intended to cover In these situations a reference to quantitative values that have been recommended for average users may be provided as a minimum Part I Executives Guide To Accessible Design Resource Guide for Accessible Design of Consumer Electronics 1 Introduction 1 INTRODUCTION This document is the result of an industry initiative by the Electronic Industries Association s Consumer Electronics Manufacturing Association E A CEMA and the Electronic Industries Foundation EIF to provide consumer electronics manufacturers with the engineering tools they need to significantly enhance the usability of their products It is intended to provide guidelines to designers of consumer electronics to facilitate the design of products that are accessible to a wider range of individuals including individuals with functional limi
75. ing upon the function of the button or control they are associated with Since dynamic labels will be unusable by blind product users a redundant means of labeling or identification should be used EXAMPLE ATM display labels located on screen next to function buttons are dynamic labels In order to be usable by the blind consider providing tactile labels next to the buttons off screen that cover at least the most commonly used functions of the ATM Providing auditory labels as well as visual dynamic labels is another means of making a product more accessible REFERENCE EIA 1994 Pictograms When pictograms are used as labels they should be accompanied by equivalent text information This will make it easier for visually impaired users to identify them REFERENCE EIA 1994 115 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Documentation Labeling 4 2 4 4 2 7 4 2 4 Size 4 2 5 4 2 6 4 2 7 A range between 16 and 20 point print size is recommended for the labels It is recommended that letters and numbers used in the label should have e height to width ratio between 1 0 7 and 1 0 9 e a stroke height to width ratio between 12 1 and 3 75 1 COMMENT Some users with visual impairments prefer print sizes normally considered to be large print while others are not able to read the same display even with good magnification Extremely large characters are difficult for some people t
76. inguishable from the main surface Since the buttons on the radio incorporate several of these raised with a recessed surround and tactile labels it was determined that including dished centers was not necessary Once recommendations for changes have been made the associated trade offs should then be evaluated and the final changes determined Cost is the most common trade off with implementing changes If a change requires a high cost with little benefit to the accessibility of the product then the improvement may not be warranted There may also be trade offs between different types of accessibility For example changing the slide controls to make them easier to move may increase the likelihood of accidental activation Improvements should be carefully designed so that they do not bring about new problems Size and space as well as design appearance are also trade offs that must be considered The following table lists several recommendations that resulted from the evaluation of the clock radio and possible trade offs that must be considered 51 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example Recommendations Tradeoffs 1 Increase the size of the FAST and SLOW buttons Controls easier to operate Requires more space may reduce separation fal Increase the separation between the FAST and SLOW Controls easier to operate Requires more space buttons Move the time set lock to the left s
77. ion If a particular checklist item has direct application to the product or if more information or understanding is needed the designer should reference the more complete information provided with the associated guideline in Part 3 Designers may choose to review the guidelines in Part 3 before conducting an evaluation using this checklist 28 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist s satisfactory M marginal U unsatisfactory 1 0 Controls Guidelines General Selection Proper control for task Shape size and texture Easy to hold and grip Location Easy to access 1 1 4 Orientation Vertical for precision Horizontal for power 1 1 5 Force required Minimal strength required Short duration of operation Simultaneous manipulation No simultaneous motions required 1 1 7 Preventing accidental activation 7 Action can be reversed If activation is serious prevention methods used 1 1 8 Labeling Placed horizontally Visible and descriptive Coding Redundant methods used 1 2 1 Shape Discriminable by touch Associated by function No more than five different shapes Texture Smooth knurled or fluted 1 2 3 Size No more than three different sizes Combine size coding with texture coding 1 2 4 Redundant color coding Combine color with size shape or texture coding 29 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Che
78. ions such as pushing while turning or pressing several buttons simultaneously Twisting motions may be especially difficult For individuals with arthritis controls that require pinching or rotating are difficult to operate In addition functionally limited individuals are unable to exert as much force on controls as individuals without functional limitations Individuals with poor muscle control may find it difficult to make fine motor movements with their fingers and may be restricted to gross movements with their hand s Some individuals with physical disabilities may have to rely on assistive devices in the use of products Individuals with spinal cord injuries may be unable to use their limbs and may use manipulation aids such as mouthsticks prosthetics orthotics or reachers Other assistive devices include mobility aids such as crutches or wheelchairs communications aids such as artificial voices and computer device interface aids such as eyegaze operated keyboards Vanderheiden amp Vanderheiden 1991 10 Vanderheiden amp Vanderheiden 1991 1 Kanis 1993 12 Vanderheiden amp Vanderheiden 1991 18 Resource Guide for Accessible Design of Consumer Electronics 5 Functional Limitations Deafness and Hearing Loss Deafness and hearing loss is one of the most prevalent disabilities Approximately 22 million people U S have hearing impairments Of these 2 4 million have severe to profound impairments Individua
79. irect manipulation of data and can save valuable screen space When using icons there is less of a need for translation when the product is an international one Icons should be designed for legibility Their meaning should be evident and not confusing Appearance Consider the same brightness size and contrast design principles used for alphanumeric displays COMMENT Combine type and graphic symbols when possible and use high contrast between the graphics and background RELATED GUIDELINES 2 3 1 2 4 1 2 4 7 REFERENCE Haigh 1993 2 5 2 Recognition Graphic symbols or icons should be designed to look like the object they represent and should be tested with a representative group COMMENT All icons or graphic symbols should be distinguishable from other icons or symbols COMMENT Graphic symbols should be tested to ensure that symbols are distinguishable from each other and convey the intended message Consider including visually impaired individuals in the testing REFERENCE Cushman and Rosenberg 1991 Wright and Barlow 1995 95 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Graphics Icons_ 2 5 3 2 5 3 Identification The detail provided in an icon should be minimized so that only important identifying features are shown Simple concrete symbols are preferred over abstract complex symbols COMMENT Provide a means for the user to identify unknown symbols EXAM
80. is time well spent Customer documentation should be provided in both large print and alternative formats for example audio recordings Braille computer disk By providing users with more than one way of accessing information the probability that the user will actually obtain the information they need is increased The following is a listing of the features and design issues that will be addressed in this section 4 1 General 4 2 Labels 4 3 On line documentation 112 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 4 1 4 1 6 Documentation General 4 1 4 1 6 General Margins and Character Spacing Flush left and ragged right margins are recommended Proportional spacing should not be used because inconsistent spacing can be confusing REFERENCE EIA 1994 Fonts Avoid script italics and oblique fonts Extended or condensed type styles should not be used Simple serif fonts are recommended REFERENCE EIA 1994 Underlining Underlined material should have a clearly discernible space between the line and the characters to be read REFERENCE EIA 1994 Character strokes Solid lines should be used to form character strokes avoid characters that have breaks in the strokes Good ratios between the thickness of the character strokes and the open area within each character must be maintained Although character strokes must be well defined thick lines can mask overall charact
81. issues The EIA CEMA and the Telecommunications Industries Association TIA are represented on this commitee Recent federal regulations also have required closed captioning to be broadcast and available on all televisions size 13 inches or larger Notice of Inquiry docket 95176 need reference for receiving equipment and volume controls available on telephones Rulemaking 8784 There are of course special exceptions to many of the requirements mentioned However there is an obvious trend in Federal regulations to require more and more access for the disabled in public places and in businesses There is a similar trend for accessibility of information including information infrastructures such as the Internet Many requirements such as video captioning are expected to be required of information available to the public through the Internet Mass market consumer products that meet the needs of both the average individual and the needs of the disabled will be best positioned to serve these markets Resource Guide for Accessible Design of Consumer Electronics 3 Benefits 3 BENEFITS Aside from the humanitarian reasons for making products more accessible there are a number of economic benefits to increasing product accessibility The most obvious economic benefit is the increase in potential customers gained by making a product more accessible Individuals over the age of 65 are the most likely to have functional limitations and also have the g
82. itch on the right turn the switch to ON to turn on the radio Rotate the TUNING knob to tune the radio and rotate the VOLUME knob to change the volume The band can be changed from AM to FM using the slide switch labeled BAND The radio can also be turned on by pressing the SLEEP button This button turns on the radio and turns it off after a period of time up to one hour The amount of time that the radio stays on can be changed by holding down the sleep button as the display counts down from 59 minutes to the desired time The alarm clock is set by placing the SELECTOR slide switch to ALARM if one wishes a buzzer alarm and to AUTO if one wishes to wake to radio The time of the alarm can be seen by pressing the ALARM button The time display will change to display the alarm time The alarm time can be changed by holding down the alarm button and pressing either the FAST or SLOW time set buttons The alarm time can be quickly reset to 12 midnight by holding down the alarm button pressing both the fast and slow buttons The alarm also has a snooze function This function is activated by pressing the SNOOZE button when the alarm is going off This function turns off the alarm for nine minutes at which time the alarm will resume Unless another button is being pressed the current time is displayed in the time display The display includes and AM and PM indicator The time can be displayed
83. ivating controls if the forces required are higher than the ones given REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 67 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Pushbuttons 1 5 7 1 5 9 1 5 7 Contrast Light controls on dark backgrounds with a preferred contrast ratio between 6 1 and 15 1 COMMENT Greater contrast ratios are better and would facilitate use by the visually impaired An absolute minimum contrast ratio is 3 1 COMMENT If poor contrast is unavoidable it should be compensated for by increasing the size of the pushbutton This compensation will help visually impaired users to identify and use the button REFERENCE Cushman and Rosenberg 1991 EIA 1994 1 5 8 Location Pushbuttons should be mounted in the horizontal plane COMMENT Positioning in the vertical plane below the seated elbow height gives the poorest performance REFERENCE EIA 1994 1 5 9 Accidental Activation A switch guard should be provided for critical switches COMMENT It is good to have an acceptable delay of 1 to 2 seconds before activation REFERENCE EIA 1994 68 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Keyboards Keypads_1 6 1 6 5 1 6 Keyboards Keypads see also Pushbuttons Some things to avoid when using keyboards or keypads are multiple finger simultaneous operations and auto repeat
84. izontal array ie ile fl Installed for vertical orientation eS a nas Movement up right or forward turnson 0 1 12 1 Travel distance EH Preferred distance of 40 to 60 degrees Feedback ae tactile or visual feedback _ 1 12 3 Separation a E e A From 0 75 to 2 0 between switches ODS SEY 1124 Sze o S From 0 25 to 1 0 inthickness width O O OE From 0 5 and 2 0 in length Cp a C ey 1 12 5 Force EH Requires from 10 oz to 40 oz of foree S E 1 13 Push Pull Controls Not Recommended Le a ae Mouse S O 1 14 Mouse Easily fits in palmar grasp rounded back Wide top front surface EP Buttons on front surface P Auso feedback sey let ff Top surface has matte texture to a ee Textured gripping surface on sides 7 1 14 2 Feedback o e Good tactile and auditory feedback _ o 1 14 4 Accidental Activation o Stiff buttons to support resting fingers S Audio feedback if used by blind S Adjustable for fine and course motions Z o S 115 1 Feedback S Adequate tactile feedback from ball oo 1152 Sie PE 2toSimchesindiameter o 100 degrees surface exposure o Palm wrist clearance of 4 75inches_ o Clearance around the ball of 2inches S 35 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist G
85. l and fore and aft rather than lateral COMMENT Movement of the control to the right will result in a movement to the right a right turn or right bank of a vehicle REFERENCE Bailey 1989 1 4 5 Consistency Every piece of equipment that a person uses should have the same control display motion relationship REFERENCE Bailey 1989 65 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 5 1 5 1 1 5 2 Controls Pushbuttons 1 5 1 5 2 Pushbuttons Some things to avoid when using pushbuttons are multiple finger simultaneous operations and auto repeat activation as the pushbutton is held down Also a button that is not depressed should indicate an off condition while a depressed pushbutton should indicate an on condition COMMENT For mobility impaired users simultaneous button presses may be difficult and an auto repeat function may create problems for users who do not have much finger dexterity REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Surface The surface of pushbuttons should be easily differentiated tactually from the main surface of a product such as by a matte non slip surface or by being recessed raised or contained within a raised boundary Having the center of the button slightly dished is also recommended Texture can also help to differentiate buttons that have important or unusual functions EXAMPLE An embossed dot on recording c
86. lay for a range of the user population including those with low vision to ensure display visibility for all users REFERENCE Salvendy 1987 2 1 6 Size The minimum acceptable display size depends on the type and amount of information that is to be presented at one time and the viewing distance Adjustable image sizes are recommended for electronic displays to accommodate the visually disabled See the section on alphanumeric displays for recommended text character size RELATED GUIDELINE 2 3 1 REFERENCE Cushman and Rosenberg 1991 Vanderheiden and Vanderheiden 1991 Maintainability Materials should be chosen that resist aging and wear EXAMPLE The bubbling and expanding of non heat resistive surfaces on Automatic Teller Machines ATM can destroy the tactile nature of the Braille labels making them unintelligible to the blind user COMMENT Sunlight rain cleaning detergents and vandalism are often responsible for damage to equipment over time REFERENCE Salvendy 1987 2 1 8 Standardization Use standard words and symbols for your industry industry recognized whenever they exist COMMENT Although some existing standards may not follow these recommendations they are usually well established and it might be confusing to introduce new symbols It is preferable to use well recognized industry standards over new symbols or words REFERENCE Salvendy 1987 88 Resource Guide for Accessible Design of Consumer Electr
87. lity is a desired feature for all users since for example people with normal hearing may have to use a system in a noisy environment or people with normal vision may have to read a display under bright conditions 3 Provide Alternatives Redundancies Another method of ensuring accessibility for a wide range of individuals is to provide alternative methods of performing functions and to present information in redundant formats or codes Providing alternatives or redundancies also resolves conflicts that present themselves when designs for individuals with one type of functional limitation for example low vision make a product less accessible for individuals with a different type of functional limitation such as hard of hearing 14 Resource Guide for Accessible Design of Consumer Electronics 4 General Design Principles Examples of alternative methods of performing functions include 1 the capability to perform all tasks with either the keyboard or the mouse 2 the capability to perform functions with either voice or manual input 3 the capability to perform tasks using simple step by step menus or through fast shortcut keys and 4 the capability to use dedicated buttons or on screen controls Examples of using redundant information presentation formats include the presentation of both visual for example with an on screen message or light and auditory for example using tones or speech information or the presentation of both text and Br
88. lity of a user making an error If a user does make an error simple methods should be provided for undoing the actions or for returning the system to the previous state Since disabled individuals may be more likely than the average user to make errors for example because they misread a message or have poor motor control and made an incorrect selection it is even more important that designs be forgiving in order to be accessible Forgiving designs provide warnings confirmation messages and or cancel options for actions that cannot be made reversible Forgiving designs also provide default settings for the system to which a user can easily return These may be software settings or they may be mechanical default settings Controls that have several discrete states are easier to use than continuous controls An undo function that allows users to undo the previous action and return to the previous state is another example of a feature that makes consumer electronics products forgiving 7 Strive First for Accessibility then for Compatibility Direct accessibility refers to incorporating design features that allow a product to be more accessible in its original form That is the product is accessible to both average and functionally limited individuals without requiring accessories or modifications Designers should strive to create products that are directly accessible first There may be simple and low cost adaptations to current design
89. ll Inc 1992 Travel distance The switch should travel from 30 to 120 degrees with 40 to 60 degrees being preferred REFERENCE EIA 1994 Honeywell Inc 1992 Feedback Types of feedback recommended include e elastic resistance in such a way so that resistance increases gradually and then decreases as the desired position is approached so that the control will snap into position e auditory an audible click e tactile e visual indicator light liquid crystal display REFERENCE EIA 1994 Honeywell Inc 1992 Separation There should be 0 75 to 2 0 inches of separation between switches REFERENCE EIA 1994 Honeywell Inc 1992 Size The recommended sizes for toggle switches are e the thickness width should be between 0 25 and 1 0 inches e the length should be between 0 5 and 2 0 inches REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Force Activation should require between 10 and 40 oz of force REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 79 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Push Pull Controls 1 13 1 13 Push Pull Controls Push pull controls are not recommended for the following reasons e for activation they require simultaneous grasping and pulling e the position setting of the control is not apparent without visual reference and is sometimes ambiguous even with vision REFERENCE
90. ls are classified as deaf it they can only hear sounds that reach 90 decibels 5 to 10 times as loud as normal speech Individuals have a mild hearing impairment if they can only hear sounds that reach 20 40 decibels and a moderate hearing impairment if they can only hear sounds that reach 40 55 decibels The percentage of the population that is hard of hearing increases with age Twenty three percent of people aged 65 74 and 40 of those over age 75 are considered hard of hearing There are two types of hearing impairments sensorineural and conductive Sensorineural hearing loss involves damage to the auditory pathways including sensory receptor elements in the cochlea the auditory nerve or the higher processing center Conductive hearing loss involves damage to the outer or middle ear which interferes with sound waves reaching the cochlea Hearing loss due to aging also known as presbycusis is a sensorineural hearing loss and is the 14 most common auditory disorder The principal functional limitation of individuals with hearing impairments is difficulty or inability to receive auditory information Blindness and Low Vision Visual impairments affect approximately 1 8 million people 820 000 of these people are severely impaired and 580 000 of them are legally blind A person who is classified as legally blind has visual acuity of 20 200 or worse after correction or has field of vision less than 20 degrees in the best eye afte
91. luded 3 1 8 Ambient Sound Minimal noise produced by product Type of Sound Uses sounds that contrast with the sound environment Tones and Beeps Frequency Range Strong mid low frequency sounds Ranges from 300 3000 Hz lower frequencies for alarms and urgent messages Adjustable Frequency fed Provides an adjustable frequency for a wide range of users N p 2 2 3 1 9 Lal 3 2 3 Variety For different types of information uses a variety of complex tones sound and speech 3 2 4 Auditory coding Uses no more than 4 different frequencies Uses at most 3 different loudness leves oo y O Uses at most 2 different sound durations SS O Uses at most 6 combinations of the above SS O 3 2 5 Tactile aids i Provide information redundantly with tactile aids for hearing impaired 41 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines S M U Comments 3 3 Warning Signals 3 3 1 Sound level of warning signals ee ee Exceeds normal sound level by 15 dB or exceeds maximum sound level by 5 dB for 30 seconds Frequency range for warning signals gt S Signal frequency from 400HZto1500Hz 3 3 3 Signal pattern for warning signals gt rr Uses harmonic variation including increasing intensity modulating amplitude and varying frequency for warnings 41 Complexity TT PP Speech used for complex mess
92. ly benefit everyone and not just the functionally disabled Accessible design increases development time and cost Improving accessibility does not necessarily increase development time and cost If accessibility is considered in the initial design process rather than added on there should be little or no increase in development time or cost Accessibility can be considered just like any other factor such as appearance usability and cost when making decisions in the initial design process For example when designers choose a control for their product they weigh a number of different factors that affect their choice adding accessibility as one of those factors should add relatively little if any time to the process In addition evaluation of products for accessibility does not have to be a long and expensive testing process Short inexpensive user tests may be used or companies may simply choose to use a heuristic method of evaluating products using tools such as the checklist provided in this document Accessible design will increase the cost of the product The cost of accessible design is minor compared to the benefits gained In many cases accessible design does not require increased product costs If a product design does require an increase in development or manufacturing cost this cost will inevitably be passed on to the consumer in terms of cost of the product However if accessible design is incorporated into mainstre
93. most frequently used controls time alarm set to front of clock radio and less Requires minor costs of redesign frequently used controls tuning band display brightness to back while maintaining separation between controls that are confusable volume amp tuning 14 Position control labels so that they are not obstructed Easier visual access Minor costs of redesign by controls Functional Description of New Design After the recommendations and trade offs are evaluated the new design can be finalized The new design is displayed below Most of the recommendations above were implemented with the exception of 11 and 12 The radio labels were not increased because the radio can be tuned without seeing the labels using only auditory feedback from the radio Also individuals who cannot hear the radio to tune it will not have a need to tune it The controls were not moved to a single surface on the clock radio because it would require a major design change and may make it more difficult to remember the location and position of different controls on the radio than the current design However the position of the side controls was changed to provide better physical and visual access to the most frequently used controls 52 Resource Guide for Accessible Design of Consumer Electronics 8 Accessible Design Example Improved Clock Radio qune O ALARM OFF galeco youn 10 AM pat O
94. mpaired users REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Feedback Types of recommended feedback include e auditory an audible click e visual graphics liquid crystal display e proprioceptive the distance between discrete positions should be discriminable e tactile REFERENCE FIA 1994 Separation There should be a minimum of 1 inch separating switches REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Size Switches should be 0 5 in above the surrounding surface and 0 25 to 1 0 in wide REFERENCE EIA 1994 Honeywell Inc 1992 Force Activation should require between 10 and 16 oz of force REFERENCE EIA 1994 Honeywell Inc 1992 Accidental Activation Sufficient static friction reduces the probability of accidental operation REFERENCE FIA 1994 78 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 12 1 12 1 1 12 2 1 12 3 1 12 4 1 12 5 Controls Toggle Switches 1 12 1 12 5 Toggle Switches The control tip of a toggle switch should be a smoothly blending hemi sphere with the rest of the switch body A series of toggle switches should be mounted in a horizontal array rather than vertical for speed and ease of operation Install toggle switches for vertical orientation where moving the handle up right or forward turns the device on REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywe
95. n 1991 3 1 6 Redundant presentation Present information redundantly in visual form to communicate effectively with the hearing impaired especially in noisy environments EXAMPLE A built in visual ringer visible from greater than 10 feet or compatibility with visual ringer adjuncts is desirable for communication with the hearing impaired EXAMPLE Closed captioning on TVs provides redundant visual cues for auditory information COMMENT Consider providing an optional remote audio visual or tactile indicator COMMENT Features such as closed captioning are often used by individuals who are not hearing disabled for example in a noisy environment or so as not to disturb others REFERENCE Vanderheiden and Vanderheiden 1991 EIA 1994 3 1 7 Headphones Provide a headphone jack to enable a person with impaired hearing to listen at high volume without disturbing others or to isolate themselves from background noise COMMENT Providing a headphone jack is also useful for people without hearing impairments REFERENCE Vanderheiden and Vanderheiden 1991 106 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Auditory Displays General 3 1 8 3 1 9 3 1 8 Ambient sound Minimize the ambient sound produced by the product so that confusing audio signals are eliminated REFERENCE Haigh 1993 3 1 9 Type of Sound Use sounds that are in distinct contrast to the sound environment EXAMPLE Use vo
96. n achieve 4th 7th grade level cognitive abilities function well in the community and hold semi skilled jobs Individuals with moderate retardation are trainable usually live in group homes and work in sheltered workshops One to eight percent of school aged children and youth have specific learning disabilities that selectively interfere with development integration and or demonstration of verbal and or non verbal activities including speech impairments described below Age related cognitive impairments include Alzheimer s disease and dementia Individuals with Alzheimer s disease experience progressive intellectual decline confusion and disorientation Individuals with dementia experience progressive loss of mental functions Most perceptual and cognitive limitations can be categorized as e Memory limitations difficulty recognizing and retrieving information e Perceptual limitations difficulty taking in attending to and discriminating sensory information e Problem solving limitations difficulty recognizing a problem identifying choosing and implementing solutions and evaluating outcomes e Conceptualizing limitations trouble with sequencing generalizing categorizing cause and effect abstract concepts and comprehension e Language limitations described separately in the following section Individuals with perceptual and cognitive limitations generally benefit from simple displays low langu
97. nsure that a color blind user will not miss any important information use colors that vary in intensity have sufficient brightness contrast so that the color itself is not the only source of information In addition make color codes redundant with other codes COMMENT In addition to helping those with color blindness redundancy in information presentation can help ensure the message is understood cross culturally Color associations in different cultures may differ from the generally recommended guidelines color should not be the only means of coding EXAMPLE Redundancy can also be accomplished by supplementing color coding with shape or relative position coding RELATED GUIDELINE 2 6 3 REFERENCE Bailey 1989 Vanderheiden and Vanderheiden 1991 2 6 5 Define Color Codes Ensure that color codes are well defined Use standard codes if possible COMMENT Military standards exist that identify specific color coding for displays e RED is used to alert an operator that the system or part of system is inoperative For example red may mean Error Failure or Malfunction e FLASHING RED is used to denote emergency conditions that require immediate attention e YELLOW is used to advise an operator of marginal situations in which caution is necessary or unexpected delay may be encountered e GREEN is used to indicate a fully operational system that all conditions are satisfactory e WHITE is used to indicate system condi
98. o read because you have to move your eyes to see the whole character RELATED GUIDELINES Alphanumeric Displays 2 3 REFERENCE Cushman and Rosenberg 1991 EIA 1993 EIA 1994 Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Wright and Barlow 1995 Characters A simple character design should be used If embossed characters are used they should be comprised of sans serif upper case characters made of thin lines of at least 1 mm in height EXCEPTION Braille overlays with adhesive backings are appropriate labeling options for Braille readers RELATED GUIDELINES Alphanumeric Displays 2 3 REFERENCE EIA 1994 Spacing Interline spacing is optimized by using 1 1 2 times capital letter height baseline to baseline REFERENCE EIA 1994 Contrast Characters should contrast with their background light characters on a dark background is preferred to dark characters on a light background Color may be used but characters should have good brightness contrast as well as good color contrast RELATED GUIDELINES 2 4 1 2 6 2 REFERENCE EIA 1994 116 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Documentation Labeling 4 2 8 4 2 11 4 2 8 Identification Do not leave items up to the interpretation of the user and assume that the users will be able to identify every item from his or her own experience Label completely and clearly COMMENT Context plays an important part in how unl
99. onics 10 Design Guidelines 2 2 2 2 1 2 2 2 2 2 3 Displays Position and Viewing Angle 2 2 2 2 3 Position and Viewing Angle The capacity and limitations of the user and the requirements of the task at hand should be considered when determining the optimal arrangement of visual displays In general all visual displays should be multi directional when possible and highly visible Thus determining the position or viewing angle is often of primary importance to the designer Position Displays should be positioned so that they may be viewed by all potential users To be visible from wheelchairs displays should be located 40 inches from the floor COMMENT The positioning of a visual display should be used to communicate importance order and relationship of components controls and operations COMMENT Characters on a text display should be readable from any location within 45 degrees of a line perpendicular to the surface of the display COMMENT If a visual display cannot be made physically accessible or entirely visible to individuals in wheelchairs redundant audio output in addition to the visual display should be provided REFERENCE Honeywell Inc 1992 Vanderheiden and Vanderheiden 1991 Viewing angle Designers should test displays for the range of situations in which it will be used and for the range of potential users Although viewing angle estimates from seated positions may be similar to estimates from st
100. ontrols on tape recorders or power switches on appliances is a helpful tactile reminder COMMENT It is important for visually impaired users to know tactually where the controls are In addition mobility impaired users will benefit when the texture of the button is matte and non slip REFERENCE EIA 1994 Honeywell Inc 1992 Travel distance It is recommended that a pushbutton should travel at least 0 125 to 1 5 inches for finger and palm activation There should be variable resistance that gradually builds up and then drops suddenly on actuation COMMENT The travel distance of the pushbutton should be enough to make it obvious that it has been activated but not so far that it is difficult for mobility impaired users to activate it REFERENCE EIA 1994 Honeywell Inc 1992 66 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Pushbuttons 1 5 3 1 5 6 1 5 3 Visual and auditory feedback There should be visual and auditory feedback provided There could be an auditory click when the button is pushed as well as a visual indicator of on off status EXAMPLE An indicator light or liquid crystal display that indicates activation COMMENT If the pushbutton has a spring return it is necessary to provide some visual feedback of activation For visually impaired users the auditory click will provide adequate feedback For hearing impaired users the indicator light will provide adequate
101. or 5 cm COMMENT A larger separation between rotary knobs will be beneficial t o both mobility impaired and vision impaired users REFERENCE Salvendy 1987 Toggle Switches For easy activation toggle switches should be at least 1 inch apart and optimally 2 inches apart COMMENT A larger separation between toggle switches will be beneficial to both mobility impaired and vision impaired users REFERENCE Salvendy 1987 Foot Controls Fine motor control of the feet can be more difficult than for the hands therefore the required separation between foot controls should be double the separation for hand controls For foot pedals there should be at least 2 inches separating the pedals and optimally 4 inches COMMENT A larger separation between foot controls will be beneficial to both mobility impaired and vision impaired users REFERENCE Salvendy 1987 63 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 4 1 4 1 1 4 2 1 4 3 Controls Arrangement 1 4 1 4 4 Arrangement Access Controls should always be located so that users can have direct physical and visual access to them The most frequently used controls should be placed in the most accessible positions EXAMPLE Telephone jacks should be located towards the front of the telephone in order to allow easy access REFERENCE Bailey 1989 EIA 1994 Grouping for compatibility Controls should be grouped for comp
102. plays can be used to provide both qualitative e g 3 zone temperature gauge on automobile and quantitative information e g digital watch This section of the document provides a number of guidelines for designing visual displays Many of the guidelines are general benefiting all users but several have implications for specific groups of disabled users Specifically the guidelines can be used to benefit individuals with physical visual and cognitive disabilities When there are exceptions to this or additional groups of users will benefit there will be a note to that affect following the guideline The following is a listing of the features and design issues that will be addressed in this section 2 1 General 2 2 Position and Viewing Angle 2 3 Alphanumeric Displays 2 4 Brightness amp Contrast 2 5 Graphics and Icons 2 6 Color Dh Indicators 2 8 Information Presentation 86 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 1 2 1 4 Displays General 2 1 2 1 4 General Conspicuity The display should attract attention and be located where people will be looking COMMENT The three main factors that determine the amount of attention people devote to a display are prominence novelty and relevance REFERENCE Salvendy 1987 Emphasis The most important words should be emphasized EXAMPLE A display that emphasizes the word danger in a warning message by using la
103. r correction Legally blind individuals may still retain some perception of shape or contrast or perception of light versus dark Braille is preferred by only 10 of the blind Other methods of presenting textual information to the blind include auditory presentation or the use of raised letters Individuals with low vision may have the following problems after correction 13 Honeywell 1992 14 Honeywell 1992 S Honeywell 1992 16 Honeywell 1992 19 Resource Guide for Accessible Design of Consumer Electronics 5 Functional Limitations dimness of vision e spots before the eyes haziness e color distortions film over the eye e visual field defects foggy vision e tunnel vision extreme near or farsightedness e no peripheral vision distortion of vision e abnormal sensitivity to light or glare and double vision night blindness Individuals who are visually impaired have the most difficulty with visual displays or other visual output using controls where labeling is dependent on vision and with written operating instructions A number of changes in vision due to aging affect individuals ability to use consumer electronics These changes include Decrease in visual acuity a 60 year old requires three times as much light as a 20 year old to see an object Reduced powers of accommodation the older eye loses its ability to focus on near objects The average distance of near point accommodation is 8 cm at
104. rate on flashing indicators is 2 to 5 times per second with a nominal duty cycle time on of 50 percent REFERENCE Brown 1988 100 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Visual Indicators 2 7 5 2 7 7 2 7 5 Redundant Visual Feedback 2 7 6 Use visual status indicators as redundant feedback of auditory signals of feature programming feature operation states and call progress information for individuals with hearing disabilities EXAMPLE Flashing lights to indicate a ringing telephone or a busy telephone line are helpful to the hearing impaired REFERENCE EIA 1994 Redundant Auditory Feedback Provide all important visual information such as alarms or warnings redundantly in audio and or tactile form to accommodate the visually impaired COMMENT Accompany visual cues and warnings by sound one component of which is of mid low frequency 500 3000 Hz COMMENT Make information which is visually displayed both text and graphics also available electronically at an external connection point standard or special port to facilitate the use of special assistive devices e g voice synthesizers Braille printers preferably in an industry standard format REFERENCE Vanderheiden and Vanderheiden 1991 2 7 7 Labeling All status indicator lights particularly status indicators should be labeled coded e g color and positioned adjacent to the associated con
105. rds Pictures or icons should accompany words whenever possible Depending on the type of information conveyed symbols may be more or less appropriate COMMENT Symbols are more appropriate for concrete information whereas words are more appropriate for abstract information COMMENT Pictorial features can be useful for position orientation and dimensional space for example map displays REFERENCE Vanderheiden and Vanderheiden 1991 2 8 7 Digital readouts Provide digital readouts for product generated numbers where the numeric or precise value is important Use analog displays with moving pointers when relationships or trends are important REFERENCE Cushman and Rosenberg 1991 Vanderheiden and Vanderheiden 1991 103 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 3 0 Auditory Displays A display whether utilizing a visual or nonvisual channel is a device designed to convey information about a system to an operator The visual display channel addressed in the previous section is the channel of choice for conveying information about a complex system at high rates of transmission However in some task environments a nonvisual display channel may be preferred This is often the case where the displayed information occurs randomly and must immediately capture the attention of the operator Thus alerting warning and alarm displays are usually auditory channel displays and may send information re
106. reatest amount of disposable funds for consumer products Accessible design also benefits individuals without functional limitations Features that make products useful for people with disabilities and persons experiencing functional limitations normally make them convenient for everyone else Curb cuts and volume controls on public telephones are examples of design features originally intended for the disabled but frequently used by everyone Remote controls that can be operated without looking at them will be appealing to anyone who likes to watch movies in the dark not just to the visually impaired There are a number of inhibitors to designing more accessible products Fortunately many of these inhibitors are exaggerated if not completely false Following are responses to many of the arguments made which represent inhibitors to increasing accessible design The market for these products is too small for accessible design to be profitable Actually the market is quite large More than 30 million people in the U S 12 20 of the population have functional limitations Forty five percent of the population over 65 and 73 of the population over 75 have functional limitations In addition individuals over the age of 65 in the U S have the greatest amount of disposable funds to spend on consumer products Accessible design would require a major change to our established design and or manufacturing process Accessible de
107. rers expecting their products to be used with eye control devices should consider the limitations of the eye control devices and test the eye control interface with potential users Eye control devices have poorer accuracy for fixations in the lower part of the visual field They can overburden the visual system and are hard to control in vibrating or accelerating environments REFERENCE Sanders and McCormick 1987 Coupling Internal coupling of the digital wireless telephone to the hearing aid should be done either through magnetic coupling with the telecoil or other internal coupling equal to or superior to the telecoil REFERENCE Hearing Industries Association 1996 Acoustic coupling Acoustic coupling designed to minimize feedback and with adjustable volume control is recommended REFERENCE Hearing Industries Association 1996 Controls Concave and non slip buttons are better for users with manipulation devices artificial hands hooks and mouthpieces Knobs or controls that require twisting can be difficult for users with artificial hands hooks arthritis or other mobility impairments REFERENCE Vanderheiden and Vanderheiden 1991 Digital wireless telephones Digital wireless telephones can interfere with and are not compatible with some hearing aids Manufacturers should consider interference and compatibility during develop and should test their products for interference and compatibility REFERENCE Hearing Industries As
108. rger characters and borderlines satisfies this guideline REFERENCE Salvendy 1987 Legibility Legibility may be optimized by enhancing the contrast ratio of the characters against the background and by using type fonts that are easy to read such as sans serif COMMENT Optimizing legibility with larger fonts and an enhanced contrast ratio is of particular concern when designing for the visually impaired user COMMENT Designers should test a display for a range of the user population to determine how to ensure display legibility for all users RELATED GUIDELINES 2 3 1 2 3 5 2 4 1 REFERENCE Salvendy 1987 Intelligibility Make clear on the display what the message is and what may happen if the message is ignored COMMENT Use as few words as possible avoiding acronyms and abbreviations Tell the operator exactly what to do COMMENT If acronyms are necessary use only ones that are well known to the user population If abbreviations are necessary use truncated words with the first couple of letters Do not drop out letters in the middle of the word REFERENCE Salvendy 1987 87 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays General 2 1 5 2 1 8 2 1 5 Visibility The display should be visible under all expected viewing conditions COMMENT Environmental conditions such as night viewing and bright sunlight should be considered COMMENT Designers should test a disp
109. rk controls on light background Light controls on dark background are preferred with a contrast ratio of 6 1 or greater REFERENCE Cushman and Rosenberg 1991 EIA 1994 Accidental Activation Membrane keys that are activated by heat or an electric charge should be avoided because they can be activated inadvertently COMMENT Visually impaired users might lay their hands on and accidentally activate keys that are activated by temperature REFERENCE FIA 1994 71 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 8 1 8 1 1 8 2 1 8 3 1 8 4 1 8 5 1 8 6 Controls Touchscreens 1 8 1 8 6 Touchscreens Active surfaces The active surfaces of touch screens must be detectable tactually This can be done by e containing the area within a raised boundary e a textured or raised dot or symbol COMMENT Tactile identification will aid visually impaired users REFERENCE EIA 1994 Feedback Ways of providing feedback include e visual displaying the touched area in reverse video displaying a thick outline indicator light or liquid crystal display e auditory a tone or click REFERENCE EIA 1994 Separation The spacing between touch sensitive areas should be at least 0 25 inches 6 mm REFERENCE Cushman and Rosenberg 1991 Size Use large touch sensitive areas The minimal touch sensitive size should be 3 4 inches square REFERENCE EIA 1994 Accidental Ac
110. roduct is impossible Designing a product that will be usable by individuals with every type and degree of functional limitation also is impossible It is possible however to be familiar with a wide range of functional limitations so that you can identify ways to make your product accessible to a wider range of people Chapter 5 provides information that is intended to help the designer understand the capabilities of individuals with functional limitations 2 Make It Adjustable One technique that will make products accessible to a wide range of users is to make the various features of the product adjustable Providing a volume control that allows users to adjust the volume over a wide range will make products more accessible to individuals who are hard of hearing Providing for adjustable contrast brightness or even size of text or graphics that are displayed on displays will make products more accessible to individuals who have low vision Display screens should also have height or tilt adjustments so that they can be seen by people of various heights including those in wheel chairs Controls can be made adjustable so that users can specify varied levels of strength or speed needed to operate them One advantage of making products adjustable is that even though there may be an initial cost associated with adding adjustability it is much less expensive than creating different products to address the needs of various users Also adjustabi
111. s 1 4 Users have direct physical and visual Must lift radio to access bottom button access Side buttons are not visible without turning radio The most frequently used controls are More frequently used controls volume and positioned for easy access time set are placed to the back of the side panels while less frequently used controls tuning and display brightness are placed to the front Grouping for compatibility Coincides with user expectations Indicates control display relationship Grouping by function and sequence Controls with similar or related functions V grouped together Grouped according to order of use Direction of movement 1 Considers location and orientation of user y Compatible with position and response of display and or results of control movement in relation to control 4 5 Consistency Equipment uses a consistent control display motion relationship Pushbuttons No multiple finger simultaneous motions W Setting alarm No auto repeat activations y Time and alarm setting auto repeats as numbers are scrolled however this may be preferable to having to continually push the button ee indicated A e 1 5 1 E A main surface ae 1 be big enough that it s okay E al er 1 5 2 Travel distance 0 125 1 5 for finger and palm activation V 0 125 inches Increasing resistance then drop through DHR Does not increase and drop pressure press 1 5 3 Visual and auditory feed
112. s Guidelines General 2 1 1 Conspicuity Display attracts attention Display is easily visible Al Emphasis Important words emphasized 2 1 3 Legibility Enhanced contrast ratio Easy to read fonts Large fonts 16 point minimum 2 1 4 Intelligibility Clarity of message and relevant action Avoids unknown acronyms or abbreviations 2 1 5 Visibility Visible in all expected viewing conditions ml Maintainability Materials resist aging and wear 2 1 8 Standardization Uses industry recognized words symbols 2 1 6 Size Proper for type and amount of information Appropriate for expected viewing distance 2 2 1 Position At least 40 from floor for wheelchairs Audio output for inaccessible displays Text display readable from 45 angle 2 2 2 Viewing angle Good for expected viewing positions e g standing and seated 2 2 3 Printouts Printouts accessible from wheelchair 37 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelines S M U Alphanumeric Displays e o Characters as large as practical _ 20 to 22 minutes of arc visual angle oo Printed text at 16 to 20 point print size Height to Width Ratios 1 0 7 to 1 0 9 for fixed colum presentation 1 0 5 to 1 1 for proportionally spaced text Stroke width at 1 12 character height 2 3 3 Spacing Width of one stroke between characters Width of one letter between words
113. s is especially true for products that will be available to a wide range of individuals or for features such as emergency warnings Designers should be aware of text to speech technology and if necessary ensure that their products are compatible with these types of devices 23 Resource Guide for Accessible Design of Consumer Electronics 6 Where Should I Go From Here 6 WHERE SHOULD I GO FROM HERE This section is designed to help designers identify the guidelines that are applicable to their specific design situations Use the following table answering the questions as you go to obtain a list of guidelines that are pertinent to your specific application If the table lists a section of guidelines 1 1 4 2 etc then all the guidelines in that section are applicable If the table lists specific guidelines 1 4 1 1 4 4 etc then those specific guidelines are applicable Use the guideline numbers to cross reference to both the checklist items in Chapter 7 or the applicable guideline in Part 3 24 Resource Guide for Accessible Design of Consumer Electronics 6 Where Should I Go From Here Table 1 Road Map to Applicable Design Guidelines ec e go to Yes in some format 1 2 1 3 1 4 Are you considering the following types of controls 1 0 1 1 1 AJU Keyboards keypads Membrane keys Pushbuttons Rotary controls Slide switches Toggle switches Push pull controls Trackball Auditory input Are
114. s that can be incorporated directly into future releases of the product to make it more accessible If the adaptations that are required are too costly or if they negatively affect use of the product by average users then designers should consider increasing accessibility through features such as standard options accessories compatibility with third party devices or facilitation of custom modification 8 Vanderheiden amp Vanderheiden 1991 16 Resource Guide for Accessible Design of Consumer Electronics 4 General Design Principles 8 Evaluate Your Design Guidelines are of necessity general in nature They are written to apply to many different design situations and can not address all the aspects of an specific product design Because of this designers should always evaluate their designs for ease of use and for accessibility Evaluation may be as simple as stepping through the checklist provided with your design or it may entail giving your design perhaps a prototype to someone who is unfamiliar with it and asking them to walk through the functions of the product The best design evaluations for accessible products will be conducted by asking potential users including those with functional limitations to perform various tasks with a prototype of your product Chapter Seven describes different evaluation methods and provides procedures for conducting some basic evaluations of product designs 17 Resource Guide for Accessible
115. sed in conjunction with size shape texture or some other coding method REFERENCE Cushman and Rosenberg 1991 Sanders and McCormick 1987 61 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 2 5 1 2 6 1 2 7 1 2 8 1 2 9 Controls Coding 1 2 5 1 2 9 Standardization Color coding should be standardized so that the same controls on similar pieces of equipment are the same color In addition the color of the control should be meaningful to that control EXAMPLE The color red may be reserved for emergency controls only such as an emergency stop control REFERENCE Bailey 1989 Sanders and McCormick 1987 Colored lights and surfaces Color coding with lights may not be feasible in areas of high illumination unless the lights are very bright If using colored lights using only 3 different colors is recommended If using colored surfaces using only 9 different colors is recommended REFERENCE Cushman and Rosenberg 1991 Choice of colors e For users with normal color vision red yellow green white and blue are good colors to use for coding e For users with abnormal color vision red yellow green green or white cyan and blue are good colors to use for coding e If rapid identification of color is critical and some users have abnormal color vision red green or white and blue are good colors to use for coding REFERENCE Cushman and Rosenberg 1991 Location
116. sign can be implemented with only minor changes to a design or manufacturing process Improvements can be made if designers simply spend some time becoming familiar with principles of accessible design before embarking on a design Greater improvements can be made if designers will take some time evaluating a new design using established design guidelines Of course user testing of a new product is an ideal way of ensuring improved accessibility If user testing isn t currently part of the design process this would be a relatively major change however the benefits of user testing go beyond improving the accessibility of a design User testing can also identify usability problems for consumers without functional limitations and can help identify system problems before a product is complete Scadden 1994 10 Resource Guide for Accessible Design of Consumer Electronics 3 Benefits Often manufacturing processes are not affected at all by accessible design changes For example adding Braille labels on many products affects only the initial design of a mold There are no additional manufacturing costs In addition software changes require only effort during the initial design with no changes required for manufacturing In some cases for example adding an adjustment control where there had been no control previously there will be some additional manufacturing costs However these costs will be offset by the fact that these controls general
117. sociation 1996 121
118. ssible Design of Consumer Electronics 7 Design Evaluation and Checklist Guidelin eee and keypads No multiple finger simultaneous motions No auto repeat activations Indicates depressed and undepressed conditions S MU 6 1 Feedback and travel distance Positive click to indicate activation Minimum travel distance of 0 05 for small keys and 0 25 for large keys 1 6 2 Separation 0 25 minimum distance apart 1 6 3 Size From 0 375 to 0 75 in diameter orce 1 to 10 oz for alphanumeric keys 3 5 to 15 oz for numeric keys Less force for smaller keys 1 6 5 Reference keys Tactile marker for reference keys 1 7 Membrane Keys No multiple finger simultaneous motions No auto repeat activations Indicate depressed and undepressed conditions 7 1 Surface Key surface tactually different from main surface Slightly dished key center Raised edges above surrounding surface Color coded or visually marked edges 1 7 2 Feedback Tactile auditory and or visual feedback provided 1 7 3 Separation oe 0 5 to 2 0 inches apart 1 7 4 Size O O 0 5 to 1 0 inches square or rectangular 1 7 5 Force 10 to 20 oz force for activation 1 7 6 Contrast Light controls on dark background Contrast ratio of 6 1 or greater 1 7 7 Accidental Activation Avoid key activation by heat electricity a IN 32 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist Gui
119. status indicators used in conjuction with auditory signals Redundant Auditory Feedback Important visual information also provided in audio or tactile form Labeling ei Oo O RA aac a a coded Labels positioned adjacent to associated Fit control Avoid Clutter a a a re Avoids unnecessary detail and information gt eee Spacing of Information i er Doubling spacing for easier reading Enh aa Grouping o S Similar items grouped together E E Justification Le T Alphanumeric data left justified eo ll Numeric data right justified on a decimal Pf f foo Simplicity E Ge ea Language and layout as simple as possible Pf f fo Use symbols and words m Pictures or icons accompany words Digital readouts Digital readouts for any values that require precision 40 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist s satisfactory m marginal u unsatisfactory 3 0 Auditory Displays p Q T 5 2 n G Q 5 zi General 3 1 1 When to use auditory displays Used in appropriate situations 3 1 2 Tonal Messages Used when ambient noise is high Jsed when immediate response is required 3 1 3 Spoken Messages Used when detail is needed 3 1 4 Volume Control Volume adjustment with visual readout 1 5 Volume range Has wide volume range with 20 dB gain 1 6 Redundant presentation Auditory information presented redundantly in visual form 3 1 7 Headphones Headphone jack inc
120. sumer electronics Committee participation was open and invitations to participate were extended to manufacturers distributors and retailers of consumer electronics consumers and representatives of consumer organizations including those representing individuals with disabilities Representing EIA Clint Gibler then R amp D director for AT amp T s Assistive Devices Business Unit chaired the initial committee He brought to the task his extensive knowledge of and experience in assistive technologies and accessible design and a commitment to making voluntary design guidelines available to manufacturers so all consumers might benefit from accessible products This Resource Guide grew out of that commitment and the extensive involvement of many people who worked long and hard to make this guide a reality Rob Logan a user interface design manager at Thomson Consumer Electronics succeeded Clint as chair of the E A EIF Committee on Product Accessibility He deserves special recognition for his enthusiastic dedication to completing the guide Members of the committee 3 4 Dan Bart Bill Boss Mary Evans Tim Farr Don Gawley George Hanover Bruce Mahaffey Denny Mitchell Boyd Morrison Mike Paciello Stephen Sprigle Larry Scadden John Steger and Ralph Wolfe 3 4 spent many volunteer hours developing a solid foundation on which to build revise and finalize the guide As participants in working subgroups more than 50 volunteers researched the best c
121. t 1 8 million people are visually impaired A 1979 National Health Interview Survey reported approximately 30 million people in the United States 12 20 of the population with functional limitations The prevalence and distribution of disabilities changes with age groups As many as 45 of the population over age 65 and 72 5 of the population over age 75 have functional limitations The most prevalent disabilities of school age children are learning disabilities and speech disabilities while older adults suffer more from visual impairments hearing impairments and arthritis and bursitis Vanderheiden amp Vanderheiden 1991 Honeywell 1992 gt Vanderheiden amp Vanderheiden 1991 Resource Guide for Accessible Design of Consumer Electronics 2 Trends Driving Accessible Design 2 TRENDS DRIVING ACCESSIBLE DESIGN The Americans with Disabilities Act ADA of 1990 mandated that public services places of public accommodation and telecommunications services be accessible to citizens with disabilities The ADA prohibits discrimination against people with disabilities in the full and equal enjoyment of goods services facilities privileges advantages or accommodations of any place of public accommodation Public places such as hotels restaurants and stores are required to provide auxiliary aids and services and to remove architectural barriers The requirements of the ADA include requirements that information provided to t
122. tations A significant percentage of the United States population are disabled or have functional limitations as a result of injury illness or aging This number increases every year as the percentage of the population in older age groups increases The guidelines are intended for both the design of new products and the generational refinement of current products to help make them useful or accessible to the largest number of consumers The term accessible design refers to maximizing the number of potential customers who can readily use a product While no product can be readily used by everyone accessible design can impact market size and market share through consideration of the functional needs of all consumers including those who experience functional limitations as a result of aging or disabling conditions A functional limitation describes a reduced sensory cognitive or motor capability associated with human aging temporary injury or permanent disability that prevents a person from communicating working playing or simply functioning in an environment where other people in the population can function A functional limitation can be relatively minor such as a mild hearing loss or low vision or a functional limitation can be quite significant such as blindness deafness or the inability to move all or part of one s body Advanced technology has made it possible for people who are visually impaired and blind to use computers and enjoy
123. th of cut Active e The depth of cut is controlled by the large lever Passive e The small lever does not control the depth of cut Negative REFERENCE Brown 1988 Salvendy 1987 114 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 4 2 4 2 1 4 2 2 4 2 3 Documentation Labeling 4 2 4 2 3 Labeling The act of placing a descriptive word title or phrase next to a group of related information or items is referred to as labeling A well designed label will provide a means for quick identification for the user In addition labels allow the user to quickly scan a product to find an item of interest or to ensure that information has been entered correctly Highlighting labels can also help make identification easier More specific guidelines for the design of labels follow Tactile Labels Tactile labels are labels that have the text and or icon slightly raised Tactile labels are recommended and should be raised 1 32 If text is used it should be in upper case in a sans serif style EXAMPLE Tactile labels located on the back of electronic components i e computer displays can help those with low vision to make electronic connections properly COMMENT Tactile labels can assist visually impaired users in locating and identifying product labels when inadequate illumination is present REFERENCE EIA 1994 Dynamic Labels Dynamic labels are on screen labels that change depend
124. tion and response of display and or results of control movement in relation to control 1 4 5 Consistency Equipment uses a consistent control display motion relationship 1 5 Pushbuttons No multiple finger simultaneous motions No auto repeat activations et CUNE i Depressed and undepressed conditions indicated o 1 5 1 Surface oo Pushbutton surface tactually different from main surface Slightly dished pushbutton center fo 1 5 2 Travel distance T 0 125 1 5 for finger and palm activation Increasing resistance then drop through press 1 5 3 Visual and auditory feedback Auditory feedback when activated Pf fo Visual feedback when activated Pf fo 1 5 4 Separation TEP 0 5 to 2 0 apart for finger operation Pf fo At least 6 for palm activation Pf fo 1 5 5 Size 2 a 0 5 to 1 0 diameter for finger activation Pf fo 1 0 to 3 0 diameter for palm activation Pf fo 15 6 Foree o SS 10 to 20 oz for finger activation S 10 to 80 oz for palm activation S 40 less for deactivation than activation o 1 5 7 Contrast o SS Light controls on dark background e Contrast ratio between 6 1 and 15 1 P S O OS pe 1 5 8 Location Mounted in the horizontal plane ml fe 1 5 9 Accidental activation pei Switch guard provided GP A l to 2 second delay before activation oo o gt SS i O Ee E 31 Resource Guide for Acce
125. tion of the control REFERENCE EIA 1994 Honeywell Inc 1992 Separation There should be a minimum of 0 75 inches separating switches EXCEPTION The separation between switches can be minimal if they are in a row or column COMMENT The larger the separation between switches the easier it will be for mobility impaired users to activate the correct switch REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Size Rocker switches should be between 0 5 and 2 5 inches in length and between 0 25 and 1 5 inches in width REFERENCE EIA 1994 Honeywell Inc 1992 13 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Controls Rocker Switches 1 9 6 1 9 6 Force Rocker switches should require between 10 and 40 oz of force to activate REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 74 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 10 1 10 1 1 10 2 1 10 3 1 10 4 Controls Rotary Controls 1 10 1 10 4 Rotary Controls When designing rotary controls 3 12 discrete positions are acceptable Selector switches should have fixed scales and moving pointers The numbers along the scale should not be obscured when the hand is on the control In addition the pointer should come close to the index number to avoid parallax error REFERENCE EIA 1994 Honeywell Inc 1992 Sanders and McCormick
126. tion to functionally limited employees and requires that places of public accommodation not discriminate against the functionally limited In addition a number of other federal regulations exist that require accessible telecommunications to the public and require accessible electronics and information technology to Federal employees Of course another reason why manufacturers should incorporate accessible design even if they are not legally required to is because accessible design benefits American society as a whole The distribution of the cost of accessibility over a larger market actually decreases the overall costs for everyone This is because accessible design will reduce the need for benefits paid out to functionally limited either to purchase specialized equipment or because they are unable to work due to a lack of appropriate tools 12 Part 2 Designer s Guide to Accessible Design Resource Guide for Accessible Design of Consumer Electronics 4 General Design Principles 4 GENERAL DESIGN PRINCIPLES This section presents eight general design principles for designers of consumer electronics Designers should read these principles and keep them in mind while designing new products 1 Know The User Probably the most important factor in designing products that are accessible to individuals with functional limitations is understanding those limitations Knowing the specific limitations of all the potential customers for a given p
127. tions are unfavorable for spoken messages e spoken messages might annoy other persons or mask other messages REFERENCE Cushman and Rosenberg 1991 Spoken Messages Use spoken messages in situations where a high degree of message flexibility is required e g the set of possible messages is quite large or where a simple coded signal may not be able to convey adequately the message in sufficient detail COMMENT Spoken message auditory displays are also recommended in situations where the listeners have no training REFERENCE Cushman and Rosenberg 1991 105 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Auditory Displays General 3 1 4 3 1 7 3 1 4 Volume control Provide a control for sound to ensure that the loudness level can accommodate all users regardless of their sensitivity to sound COMMENT A volume adjustment that includes visual indication of the volume level is recommended for both tonal sounds and speech sounds REFERENCE Haigh 1993 3 1 5 Volume range Increase the volume range in order to help the less severely hearing impaired individuals COMMENT Make the audio output as load as practical in order to maximize the range of auditory abilities the display can address without the sound being too loud for the average user COMMENT A receiver volume control with 20 dB gain which is helpful for those with hearing loss REFERENCE EIA 1994 Vanderheiden and Vanderheide
128. tions that do not have a right or wrong such as expressing alternatives or transient conditions e BLUE is used to indicate an advisory light but due to common difficulties with perceiving blue preferential use of blue should be avoided REFERENCE Salvendy 1987 98 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines Displays Color 2 6 6 2 6 8 2 6 6 Consistency Use color codes consistently EXAMPLE If colors such as red or yellow are used for emergency or warning situations do not use these colors in other operating situations 2 6 7 Color Adjustment Provide adjustable color selection particularly for hue and intensity REFERENCE Salvendy 1987 Vanderheiden and Vanderheiden 1991 2 6 8 Color in Low Luminance Displays The sensitivity of the eye decreases with increasing age It is best to avoid color in low luminance displays if they are to be appropriate for older users COMMENT All users find it easier to appreciate colors in larger objects The smaller the object the poorer the color will appear to the eye COMMENT All users experience insensitivity of the retinal periphery to saturated red and green colors Therefore yellow and blue should be used as peripheral colors REFERENCE Cushman and Rosenberg 1991 Salvendy 1987 99 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 7 2 7 1 2 7 2 2 7 3 2 7 4 Displays Visual Ind
129. tivation Touch screens that are activated by heat or an electric charge should be avoided because they can be activated inadvertently Controls that require light pressure are desirable REFERENCE EIA 1994 Critical functions Critical functions should have a two step selection process The earlier touched function should be validated with the activation of an enter key or similar touch area REFERENCE EIA 1994 72 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 9 1 9 1 1 9 2 1 9 3 1 9 4 1 9 5 Controls Rocker Switches 1 9 1 9 5 Rocker Switches Shape Operation The two faces of the rocker switch should meet at an obtuse angle The upper away or right part of the switch should turn on start or engage the device REFERENCE Cushman and Rosenberg 1991 EIA 1994 Honeywell Inc 1992 Feedback Types of feedback preferred include e tactile a detent e auditory an audible click e visual an indicator light or liquid crystal display indicate with message especially if the rocker switch is a spring return switch REFERENCE EIA 1994 Honeywell Inc 1992 Angular travel There should be about 30 degrees of angular travel The face that is depressed indicates the present position of the control It should be back lighted to help the operator identify the position COMMENT Back lighting the switch will help hearing impaired users identify the present posi
130. tments be required e feedback how much and what kind of feedback will the user need e compatibility with user expectations population stereotypes does the control work the way the user will anticipate it to e g move right left instead of up down rotate instead of slide etc control display relationships will rotating the knob to the right create an increase in the display or a decrease The following section will provide a number of guidelines for designing controls Many of the guidelines are general guidelines but several have implications for specific groups of disabled users Specifically the guidelines can be used to benefit mobility and vision impaired users When there are exceptions to this or additional groups of users will benefit there will be a note to that affect following the guideline Controls that are specifically designed for impaired users such as handsets and eye control devices are discussed in the section on accessories and modifications The following is a listing of the features and design issues that will be addressed in this section 1 1 General 1 2 Coding 1 3 Separation 1 4 Arrangement 1 5 1 17 Specific Types of Controls 58 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 1 Controls General 1 1 1 1 5 General Selection Before selecting the type of control to be used on the product it is important to think about where the control will b
131. trol EXAMPLE Status lights on audio components VCRs copiers keyboards disk drives and modems should be labeled RELATED GUIDELINES Section 4 2 in Documentation REFERENCE Cushman and Rosenberg 1991 101 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 2 8 2 8 1 2 8 2 2 8 3 2 8 4 Displays Information Presentation 2 8 2 8 4 Information Presentation When a number of different pieces of information are presented on a single display such as on a computer screen the information should be organized in a meaningful manner Avoid Clutter Avoid putting unnecessary detail and information on the display Unneeded information degrades the user s ability to extract the relevant information COMMENT If more information is needed than will be easily presented on a single display screen partition the data into separate display pages REFERENCE Helander 1988 Smith and Mosier 1986 Spacing of Information Doubling spacing letter height to space ratio of 1 2 makes it easier to find one s way around the display by breaking up the text into logical segments and yields optimal performance Spacing and blanks are important both to emphasize and maintain the logical sequencing or structure REFERENCE Tullis 1983 Honeywell Inc Vol 25 6p 657 682 Helander 1988 Grouping Group similar items together to improve readability and highlight relationships between different
132. ue as background color only 2 2 2 Yellow or green type on black ground best Combinations of blue green and violet chosen carefully 5 6 2 6 3 Effective Color Use Color Coding Similar colors for related data Color used properly to help with formatting and distinguishing symbols 6 Color does not impair legibility of data or task performance am E p id T F Colors used in coding vary in intensity ges co a Color codes redundant with othercodes S Define Color Codes a a aa Uses standard well defined color codes ES SEY Consistency EH Color codes are consistent P f foo Color Adjustment a a ea Color adjustable for hue and intensity 2 6 8 Color in Low Luminance Displays ae Color avoided in low luminance displays Color avoided for small objects 39 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist 2 By 2 8 1 2 8 2 2 8 3 2 8 4 8 6 2 8 7 Guidelines S M U Comments Visual Indicators Visibility ff High visibility and multidirectional a Emergency indicators visible from greater I fae than 10 feet Use large bold type and unique border Not exceeded by ambient light Brightness greater than 216 foot lamberts Blink coding Used sparingly for well defined messages Uses two coding levels blink no blink Blink Rates 2 to 5 times per second Nominal duty cycle time on of 50 percent Redundant Visual Feedback Visual
133. uestions and depending on the objectives of the test can remain in the testing area with the subject or can observe the subject through a window or camera The technician is responsible for logging any comments the subject might make and keeping track of where and what the subject is doing on any given task Computerized data logging tools that record task times and allow the test technician to code errors and comments are helpful in usability tests Heuristic Evaluation A heuristic evaluation is an inexpensive fast and relatively easy way to evaluate a design It involves a group of evaluators looking at a product and judging it on a set of usability principles Each evaluator inspects the design individually As the person evaluates the design they generally write down any problems they find The following is a list of usability principles that might be used to judge a product in a heuristic evaluation Nielsen and Mack 1994 e Visibility of system status Simple and natural dialogue Speak the users language Minimize the users memory load Consistency Feedback Clearly marked exits Shortcuts Precise and constructive error messages Prevent errors Help and documentation The principles described in Chapter 4 pages 12 15 should also be considered in evaluating the accessibility of a product In order to evaluate the product thoroughly the evaluators should use the product as the intended user would The outcome
134. uidelines SMU Comm 1 16 1 Foot Pushbuttons ee a Has elastic resistance and static friction ae SEY Resistance starts low builds and drops ODS SEY 1 16 2 Foot Pedals E a ee Has elastic resistance ee a Return to null when force removed ee a a SEY 1 16 3 Displacement 2 to 4 for entire leg operation FG 2 5 maximum for ankle action BP SEY 1 16 4 Separation a i ea 4 inches separating foot pedals Ep c E 1 16 5 Force a a a 64 oz to 320 oz of force to activate D SE Auditory Input see with other visual or manual tasks Not used in stressful situations 7 1 17 1 Voice recognition o y Uses adaptive voice recognition system and or allows for updating of voice templates 1 17 2 Recognition errors a aaa The effects of recognition errors are not too great 1 17 3 Message length La ___ _ ___ _ _ Short message lengths ie a 1 17 4 Vocabulary size ee Time and order constraints on vocabulary MS 1 17 5 Recognition vocabulary Pf f fo Uses familiar terminology a Avoids acoustically similar items Cos fo SEY 1 17 6 Training a Provides system training ef Provides system practice time a ee 1 17 7 Environment TT oe it environment e avoided Feedback A E E Provides recognition feedback and corrections 36 Resource Guide for Accessible Design of Consumer Electronics 7 Design Evaluation and Checklist s satisfactory m marginal u unsatisfactory 2 0 Visual Display
135. uirements In addition the force required to manipulate controls should be as low as possible COMMENT Users that have mobility impairments do not have a great deal of strength they may not be able to use a product that requires them to hold down a control for an extended period of time or exert a lot of force to activate the control REFERENCE Kanis 1993 59 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 1 6 1 1 8 Controls General 1 1 6 1 1 8 Simultaneous manipulations Users should not have to carry out simultaneous manipulations such as pushing and rotating a control COMMENT Pushing is preferable to rotating because rotating also requires the user to pinch which may be difficult for mobility impaired users REFERENCE Kanis 1993 Preventing Accidental Activation If accidental activation of a control will cause serious problems or can not be reversed consider the following methods of designing controls that are resistant to accidental activation e Recess the controls e Isolate the control to an area in which it will be hard to unintentionally activate e Provide protective coverings over the control e Provide lock out of the control so that it cannot be activated unless unlocked e Increase the force needed to activate the control so that extra effort is required e Require a specific sequence of control actions so that one unintentional action does not activate th
136. urrent practices in accessible design and created preliminary guidelines clustered by specific limitations and or disabilities Their numbers prevent listing their names but the guide would not be a reality without their initial work Building on their work Monterey Technologies Inc under contract to EIF translated the highly technical descriptions from the working groups into this easily readable resource guide Many manufacturers and designers from member companies of EIA the Consumer Electronics Manufacturers Association CEMA and the Assistive Devices Division and staff members from EIA EIF and CEMA took time to review the draft Their responses strengthened this document In addition member companies of the Telecommunications Industry Association participated in the review as part of their work to make recommendations to the Architectural and Transportation Barriers Compliance Board on accessibility guidelines for telecommunications equipment and customer premises equipment under Section 255 e of the Telecommunications Act of 1996 To those mentioned specifically here and all others whose participation contributed to the finished product you now have our grateful thanks It is our hope that the guide will lead to stronger links between the manufacturers of consumer electronics and telecommunications products and product buyers and other users with functional limitations Molly M Mannon President Electronic Industries Foundation
137. users to know tactually where the controls are In addition mobility impaired users will benefit when the texture of the button is matte and non slip REFERENCE EIA 1994 Honeywell Inc 1992 Feedback Types of feedback preferred include e tactile detectable movement of the membrane keys about 0 02 inches e auditory an audible click or sound e visual indicator light liquid crystal display indicate with message COMMENT Visual feedback is especially important for hearing impaired users while auditory feedback is important for vision impaired users REFERENCE EIA 1994 Honeywell Inc 1992 Separation There should be 0 5 to 2 0 inches separating keys REFERENCE Honeywell Inc 1992 70 Resource Guide for Accessible Design of Consumer Electronics 10 Design Guidelines 1 7 4 1 7 5 1 7 6 1 7 7 Controls Membrane Keys 1 7 4 1 7 7 Size Keys should be 0 5 to 1 0 inches square or rectangular REFERENCE EIA 1994 Honeywell Inc 1992 Force The force required for activation should be from 10 to 20 oz COMMENT Each key should have a snap dome and permit activation with equivalent pressure anywhere within the area demarcated with the raised edges This will help mobility impaired users activate the key without having to have excellent aim REFERENCE EIA 1994 Honeywell Inc 1992 Contrast Membrane keys should contrast with their background either light controls on dark background or da

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