Computer- & screen-based interfaces:
Universal design filter

Ellen Francik
Human Factors Engineering
Pacific Bell
Version 2
June 6, 1996


Table of Contents:


Summary

This is a guide to making computer- and screen-based products and services more accessible, in accordance with the Pacific Telesis Policy on Universal Design. As recommended by the report from Pacific Bell's Advisory Group for People With Disabilities, ("Pacific Bell's Advisory Group for People With Disabilities: The Advisory Group's Recommendations and Pacific Bell's Response." For copies call 510.704.3630.) we need to consider the needs of customers with disabilities early in the development process, when it is easiest to implement more flexible designs.

This document highlights issues that customers with various disabilities may have as they try to use computer- and screen-based products and services. Pacific Bell Internet's dial-up service is a computer-based product. Movies on demand would be a screen-based product (consumer broadband video service, delivered to the TV screen).

This guide, used early in product development, will allow product teams to make more informed decisions about which markets the product serves. It will also allow product teams to plan for changes that mean greater accessibility.


About universal design

A brief definition

Creators of a consumer product want to ensure that it is appealing to customers. One aspect of that appeal is usability, the ease with which customers can learn about and routinely, enjoyably use the product.

During product development we set usability goals, test designs out with customers, and keep redesigning and testing until we meet those goals. We do this with a particular set of customers in mind, or perhaps multiple sets of customers.

In universal design we extend our definition of "the customer." We design products so that they are usable by the broadest possible group of Californians.

In particular, we design bearing in mind the needs of 5.7 million Californians who have some functional limitation affecting their use of communications products. This includes not only people with disabilities, but also older people who may not think of themselves as disabled. They don't want a special product - but they do want a product that is easy to use.

Universal design means building products that are robust and accommodating. Universal designs take account of differences in sight, hearing, mobility, speech, and cognition. Universal design helps not only people with disabilities, but also any of us when we're tired, busy, or juggling many tasks.

Importance of universal design

Universal design isn't just an ethical approach to design: it is also important to Pacific Telesis' business.

In recognition of the importance of universal design, Pacific Telesis has committed to incorporate it into product development processes. The Pacific Telesis Policy on Universal Design and other background - including extensive recommendations by Pacific Bell's Advisory Group for People with Disabilities - can be found at http://www.pacbell.com/Products /Senior_Dis/policy.html.

Universal design activities

Doing universal design means paying attention to accessibility throughout the product development lifecycle. This avoids costly retrofitting.

Product development teams need to plan for the following activities:


The GUI problem

GUIs, or Graphical User Interfaces , create serious problems for blind and low-vision customers. When applications used only text and the keyboard was the input device, it was relatively easy to create screen readers that would read text, identify input fields, and help the user navigate to them. GUIs, on the other hand, permit overlapping graphical windows, represent functions as draggable, clickable icons, and make heavy use of the mouse to activate controls. This is easy for sighted users to learn. But for users who are blind or have low vision, the screen is much more complex and using the mouse to access functions is difficult to impossible. It has been hard to develop screen readers that can infer what is on the screen and represent it well to users.

Application content is also becoming less accessible. Online information does have the potential to be more accessible than paper documents. However, the use of graphics for menus, image maps, and even whitespace control in World Wide Web documents is soaring. Sites that present critical information in graphics -- only - are inaccessible to screen reader users. They are also not usable by people with slow network connections, who often find it necessary to turn off image display in order to get to Web pages more quickly.

In addition, for people who are deaf or hard of hearing audio and non-captioned video are inaccessible. For people with physical limitations, systems that require fast responses, fine motor control, or that present information in rapidly changing forms (animations) are hard to use.

Public pressure to solve these problems is mounting. GUI platform providers like Apple and Microsoft are responding. Application developers now need to use platform services and develop well-behaved applications that work well with accessibility aids. Web browser and Web content developers will also need to address accessibility issues soon. Developers of interactive TV applications are beginning to understand the need for accessibility.

Operating system support for accessible applications

Both Apple and Microsoft are providing more flexibility and customizability within their GUIs. Developers need to write well-behaved applications that do not override these features.

Examples include:

Accessibility aids also need better methods to gather application and operating system information. In the past, the unavailability of APIs and application developers' use of non-standard user interface widgets and programming calls has hindered this.

Microsoft's solution is to standardize this interface. ActiveX Accessibility™ is intended to give applications an easy to implement method of exposing their inner workings. It also provides methods for accessibility aids to communicate directly with applications.

Interactive TV (consumer broadband) systems are each being built from the ground up, so these standard accessibility methods do not yet exist. However, users' need for access to the text on the screen, captioning of audio, and usable input devices is the same.

See the "References" section for more information on accessibility features, guidelines, and implementation.

Web content and browser design

Web pages can be designed so that, although they have non-text information, they are usable by the greatest number of people. This includes people with text-based browsers, people with slow (modem) connections, people without A/V capabilities, people with helper applications missing, and people with disabilities. The general strategy is to provide information in multiple forms so that individuals can pick the form that is easiest for them to use. Page design strategies include:

Web browsers tend to rely on mouse navigation, and screen readers can't reliably provide keyboard equivalents to those actions. More accessible Web browsers are being developed. Among their features are:

See the "References" section for more information on Web browser and page design.


Filters: Screening product concepts

What filters do

Universal design works best when it begins early in product development. Pacific Bell has created filters, checklists that help product teams anticipate potential barriers to use.

There are two filters, this one for computer- or screen-based products and another one for telephone-based products. Each filter describes the most common interactions that customers will have with that type of product, and lists barriers that customers with different disabilities may encounter.

Product teams can use the filters to refine their early product descriptions and to identify issues that need to be solved during product development.

How the filters are organized

Each filter is organized like a grid. The columns are typical customer interactions or tasks, independent of a particular product. These tasks cover all aspects of the product: ordering, installing, daily use, documentation, and help. Each individual product will involve some of these tasks, but not necessarily all of them.

For space reasons each column is on a separate page.

The filter's rows are disabilities, but also circumstances, that may affect the task. For example, someone who usually has no problem seeing may have difficulties in a dimly lit environment. Or, someone who usually has no mobility problems may have trouble picking up and using equipment if their hands are busy carrying items or driving the car. Or, someone who can hear may be in a meeting where they can't let their pager beep - so they need another way to be notified of new calls.

disabilities and circumstances grid

In the grid cells are listed issues for that combination of task and disability / circumstance. Where available, solutions are also listed.

Finally, the chart entries indicate areas that may need attention. Where available, guidelines or potential solutions are listed.

More detail on disabilities and circumstances follows.

Mobility

Hearing

Vision

Speech

Cognition


Using the filters

Scope

This filter is a checklist for product managers, product development core team members, people doing Opportunity Analyses, or anyone who is involved with new products and services during their earliest phases. It is also intended to be used by product teams in later phases of design and development, as the functionality and customer operation of the product becomes fully defined.

This filter is general. It applies to any computer- or screen-based product or service. It will alert the reader to potential accessibility problems. It will also suggest, where available, types of solutions. It is not as detailed as the platform-specific guidelines listed in the References section.

Moreover, each product has its own specific technical and market considerations, and product teams will need to determine what works best for their product.

For example, it is often useful to give audio feedback to people with visual impairments. Does that mean that every time a key is pressed the key name should be echoed back ("CONTROL," "C")? Or is it enough to give audio confirmation of the action performed ("Operation canceled.")? For accessibility questions - as with any questions about how customers will use the product - it is crucial to involve customers in the design and determine their precise needs.

Also, this filter is broad. It covers equipment (CPE) as well as network components. It covers issues that may seem beyond a single product manager's scope. Why?

Relationship to other resources

Because this filter is general and broad, it is not the final word on universal design. Consult this filter early in product development to anticipate barriers to use. Use the filter as a checklist to evaluate the product concept.

You may want assistance in:

Pacific Bell's Deaf and Disabled Market Group and Human Factors Engineering group can help. Contact information is in the "Further information" section at the end of this document.


Computer- and screen-based interface filter

1. Find out about the product

Mobility

Consider media targeted to this customer group. (The same applies for Hearing, Vision, and Speech below).

Hearing

Ensure that TV ads are closed captioned.

If product information is obtained by calling a person in a service center, TTY access is also needed. If product information comes from an interactive voice response system, TTY access to it is also desirable.

If there is TTY access to the service center, customer service representatives should be trained on TTY use and tested periodically. If there is no TTY access, customer service representatives should be trained on relay service calls. Alternative means of requesting information (mail, online) are useful for deaf and hard of hearing people.

Vision

If bill inserts are used to promote the product, provide information in the same media that are used for bills - large print, Braille, and electronic documents. Detailed product information may also be provided online.

Ensure that TV advertisements are understandable by people who cannot read the screen. Consider Audio Description.

Speech

If product information is obtained by calling a person in a service center, alternative means (mail, online, TTY) are needed.

Customer service representatives need to be trained to recognize slow, slurred, or effortful speech (dysarthria) as well as speech spoken by someone with a respirator. In some cases these customers may be using a speech relay service; service representatives should expect a slower pace of interaction.

Cognition

Provide clear identification of the product name and features, plus a way to get further information. Detailed information may be provided online or in brochures that can be read at the customer's preferred pace.

2. Order the product

Mobility

Some people may not be able to lift or handle printed material such as product catalogs. Provide it in an alternate format, such as electronically.

Hearing

TTY access to service representatives is needed. TTY access to IVR ordering systems is desirable. [See #1, "Find out about the product."]

Service representatives should be trained on TTY use or on relay service calls as appropriate. [See #1.]

Alternative means of ordering (mail, online) are useful for deaf and hard of hearing people.

Vision

Provide customer materials in alternate formats, such as large print, Braille, and electronic documents.

Speech

If product information is obtained by calling a person in a service center, alternative means (mail, online, TTY) are needed.

Customer service representatives need to be trained to serve people with speech impairments [see #1].

Cognition [no entry]

3. Install and set up the product

Mobility

Difficulties in reaching, grasping, holding, and orienting items. [See specifics in #22, "Insert or eject disk, cards, or other media," #23, "Plug in auxiliary equipment," and #21, "Access documentation or help."]

Hearing

Any training information provided in audio form will need to be available in alternative formats.

Caption training videotapes.

TTY access to help desk staff is needed. TTY access to help line IVRs is desirable [see #1].

Vision

Provide documentation in alternate formats, such as large print, Braille, and electronic documents. Note that audio tape may be more useful than electronic documents if installation requires rebooting the computer.

The installation procedure should not preclude the use of screen enlargers or screen readers. [See #7, "Read text on screen" and #8, "Browse menus."]

Need to mark identity and orientation of objects that are to be assembled. [See specifics in #22 and #23.]

Speech

If help is obtained by calling a person in a service center, alternative means (online, TTY) are needed.

Customer service representatives need to be trained to serve people with speech impairments [see #1].

Cognition

As in other areas of the product, there is a need to simplify sequences, document steps clearly, highlight important information, and automate procedures as much as possible.

4. Turn computer on/off, change settings of physical switches

Mobility

Frequently used controls need to be easily reachable, at the front of the computer. Controls that are used constantly may need wrist or arm support nearby.

People with use of only one hand can't open some laptop computers with dual latches which must be simultaneously released. People with limited dexterity can't use controls that require twist motion. People with low strength can't operate controls that require much force (>100 g). People using mouthsticks need controls that the sticks won't slide off of. Good features for controls include concave pushbuttons, rocker switches, or sliding controls. People who use alternate keyboards (sip and puff keyboard, Morse code keyboard, eye gaze operate keyboard, etc.), need computer controls that can be operated from the keyboard. Some people may be using separate units - environmental control units - to interact with and control devices in the home. This includes TVs and computers. If possible, ensure that power controls are to controllable by these units. For devices having an infrared link, people may program their unit to provide all the functions of the original home device.

Hearing [no entry]

Vision

For people with low vision, controls may be labeled with large, high-contrast lettering. Color coding needs to take color blindness into account. Recappable keys allow the use of custom keycaps with easy-to-see letters and colors. Replacement keyboards and input devices, such as "kids' keyboards," may be used here.

No control should be more than one away from a tactile landmark (corner, uniquely shaped control, nibbed control, home key). Tactile overlays may be provided for important keys (ENTER, CTRL, ALT).

4. Turn computer on/off, change settings of physical switches (continued)

Vision

People who can't see controls can't tell the status or setting of the control if the only indicator is a light. Additional cues include position/orientation of the control and audio feedback. On-screen indications of controls' status should be accessible to screen readers.

Speech [no entry]

Cognition

The following are general strategies for reducing the complexity of controls for all users. Reduce the number of controls, or hide infrequently-used controls. Make the product self-adjusting. Simplify controls. Avoid dual purpose controls.

Make labels easy to understand and put each near its control. Use simple language for labels. Color code controls as appropriate. Leave space around keys or controls for custom labels. Provide cues for sequences, reduce their length, or eliminate them. Use preprogrammed buttons for common sequences. Allow entry of a macro, or short code, for a longer sequence. Minimize lag or system response time.

Build on people's expectations. Make operation of controls follow movement stereotypes. Follow color-coding conventions.

5. Hear cueing and warning beeps, buzzers, tones, and other computer noises

Mobility [no entry]

Hearing

To help people who can't hear high or low frequencies, use sounds with strong mid-frequency components, 500 - 1500 Hz.

For people in noisy environments or who have mild to moderate hearing impairment, make default volume fairly loud (Trace Center recommendation: 77 dB) with little or no background noise in it. The set of sounds should be small and individual sounds should be easily discriminable. User control over sound type and volume can be provided in software. For greater user control over volume, a switch may be on the front of the device. To accommodate multiple users with different volume requirements, a headphone jack with a separate volume control may be placed on the front of the device. For deaf people and people in quiet environments like libraries, auditory information needs to be redundantly available in a visual form. (ShowSounds: warning beeps are replaced by menu bar flashing.) Remember that deaf people can't hear incidental information others take for granted, such as noises from the disk drive; they will need other feedback about processes that are underway. Use and document drive lights and other visual indicators as a cue that progress is normal, or not.

Vision [no entry]

Speech [no entry]

Cognition

The set of sounds should be small and individual sounds should be easily discriminable. Supplement tones with text messages as appropriate to aid interpretation.

6. Find or see graphics, pictures, or video on screen

Mobility

Physical placement and angle of the screen are important. Location, height, tilt, and swivel of the monitor should be adjustable with minimum force. Support alternate access to pointing, tracking, and scrolling features (MouseKeys, head pointers).

Hearing [no entry]

Vision

People with low vision may need screen enlarging software and larger displays. Glare on the display should be minimized.

Screen objects need good contrast. Airbrush effects make them harder to read. Animation and scrolling marquee text may make it difficult for people with low vision (with limited fields of vision who must actively scan the screen) to see or distinguish the objects.

The cursor is an important object. If it's small, users may need to have it blink or substitute a larger one.

People with color blindness may not be able to distinguish colors on the screen. Choose colors so that they vary in intensity as well as hue; color coding should be used redundantly with other cues when possible; user customization of color may be desirable.

In general, important visual cues should be represented redundantly in audible form. Ensure that all screen objects can be found and identified by screen readers. For computer applications, follow appropriate guidelines to avoid conflict with accessibility aids. For Web pages, support ALT-text and/or text versions of pages. Provide text descriptions of important images. For interactive TV applications, consider providing text equivalents for bitmapped words and objects, plus speech output. Consider Audio Description for video.

Speech [no entry]

Cognition

Use animations and dynamic displays with care. They may help to illustrate concepts, but they may also change too quickly to be grasped. Consider providing adjustable speed, or let the user control the motion.

7. Read text on screen (display or entry text, scrollable lists, error messages, prompts)

Mobility

Physical placement and angle of the screen are important. Location, height, tilt, and swivel of the monitor should be adjustable with minimum force. Support alternate access to pointing, tracking, and scrolling features (MouseKeys, head pointers).

Hearing [no entry]

Vision

Same issues as in #6, "Find and see graphics."

Readability can be maximized by using upper and lowercase type, using high contrast between text and background, and using sans serif fonts for labels.

Screen reader users need the ability to select and review the spoken or Braille equivalent of text from any portion of the screen. Applications should be designed so that it is easy to navigate to text fields and so that all text information is accessible to the screen reader. Web documents need to avoid frames, tables, or side-by-side columns of text; screen readers will read left to right across all columns. [See also #6.]

Speech [no entry]

Cognition

Same issues as in #6. Also: people may use screen enlargers or screen readers to focus their attention and increase understanding while reading.

8. Browse menus

Mobility [See also #9, "Type," and #10, "Use the mouse."]

Pull-down menus, especially on systems where the mouse button must be held down while the mouse is moved through the menus, pose problems. Trackballs with click-lock solve the problem of having to hold the mouse button down. Also, some GUIs allow a click-click instead of a click-and-drag method. Finally, most GUIs allow menus to be browsed using the keyboard.

Follow GUI guidelines to ensure keyboard equivalents for common functions. If possible, make the application entirely usable from the keyboard. Follow appropriate guidelines to avoid conflict with accessibility aids.

Voice recognition and head pointing devices are alternatives to keyboards and mice.

Hearing [no entry]

Vision

People with low vision may not be able to read the menus at their default size. Screen enlargers may help.

Ensure that menus can be found and read by screen readers. For computer applications, follow appropriate guidelines to avoid conflict with accessibility aids. For Web pages, support ALT-text and/or text versions of pages. Numbered lists and specific list headers ("list with 6 items") help people know what to expect.

Follow GUI guidelines on menu breadth and depth. This makes the menu more easily understood when read aloud by a screen reader.

Speech [no entry]

Cognition

Having the ability to browse menus is a cognitive aid, and is preferable to having to remember commands. The menus themselves, however, may become complex. Follow GUI guidelines on menu breadth and depth.

9. Type or press buttons

Mobility

Location, height, and slant of keyboard should be adjustable with a minimum of force.

Provide macros or shortcuts for frequently used sequences of actions. Use default buttons where appropriate, to minimize the number of keystrokes required.

Minimize effect of timing and timeouts on what the interface does. Allow users to proceed at their own speed as much as practical. If product requires a quick response (a reaction time of < 5 sec or release of a key in < 1.5 sec), allow the user to adjust the time interval or to have a non-time-dependent input method. This applies to key repeat rates as well as to responses to prompts. StickyKeys allows key combinations to be entered as a series of single keypresses. It helps people who can use only one arm or hand or who use a headstick or mouthstick. People with limited movement control may strike unwanted keys before targeting the desired key. These people may need a physical keyguard or FilterKeys. Some people need the ability to connect alternative keyboards (sip and puff, eyegaze). Standalone communication aids can also be used as input devices if an infrared link is provided. SerialKeys allows non-standard devices to create "authentic" keystrokes.

More specific information on desirable key force and travel characteristics is available. Voice recognition is an alternative to typing.

For issues with remote controls, see also #4, "Turn computer on/off."

Hearing [no entry]

Vision [See also #4.]

Support use of larger cursors so that the text entry point is clearly visible.

Speech [no entry]

Cognition

For issues with remote controls and other non-keyboard devices, see also #4.

10. Use the mouse

Mobility

Some people do not have enough fine movement control to grasp, move, point, and select using the mouse. Touchpads, touchscreens, joysticks, and trackballs may present similar problems. Other people rely on special keyboard-simulating input systems. All of these people need applications that allow mouse functions to be carried out with the keyboard. Solutions include: (1) using the keyboard to steer the mouse pointer around the screen; (2) using TAB or arrow keys to move between options on the screen; (3) having keyboard equivalents for mouse-activated functions.

StickyKeys may be needed to perform mouse selection modified by SHIFT or ALT. MouseKeys handles keyboard equivalents for mouse movements. SerialKeys allows non-standard devices to create "authentic" mouse movements.

Voice recognition and headpointers are alternatives to mouse or keyboard activation of functions.

Hearing [no entry]

Vision

People who are blind and some people with low vision can't use input devices which require constant eye-hand coordination and visual feedback. They need mouse alternatives like screen readers used with the keyboard. Follow GUI guidelines to ensure keyboard equivalents for common functions. If possible, make the application entirely usable from the keyboard. Follow appropriate guidelines to avoid conflict with accessibility aids.

(Note: One research system does provide speech and sound feedback for people using touchscreen kiosks.) Allow use of a larger pointer so that its position is clearly visible. Allow use of "mouse tracks," a graphic trail, to help people locate the pointer.

Voice recognition of commands may be an alternative.

Speech [no entry]

Cognition

Minimize necessity for triple-clicking or using SHIFT and ALT to modify mouse clicks. These are more difficult to remember and use.

11. Select an object on the screen (document, folder, window, button, menu, graphic)

Mobility

If the screen is easily visible and relatively static, the main obstacle here is use of the keyboard (see #9, "Type") or mouse (see #10, "Use the mouse"). For mouse use, target size affects ease of selection.

As in #9 and #10, minimize effect of timing and timeouts. Allow users to proceed at their own pace. In particular, provide alternatives to animated icons or menus that require users to respond before they change.

Hearing [no entry]

Vision

Combines difficulties of seeing the object (#6, "Find or see graphics") and navigating to it with keyboard (#9) or mouse (#10).

Speech [no entry]

Cognition

Most graphical user interfaces emphasize selecting visible items with simple clicking or double-clicking. Some of the more complex selection methods may cause difficulties: selecting non-visible items from pop-up menus; remembering and performing selections modified by SHIFT, ALT, or other keys; etc.

12. Manipulate screen objects: move, resize, drag, drop

Mobility

Same as with #11, "Select an object." Some additional difficulty in coordinating the drag motion of the mouse. Again, alternate ways of performing these functions are desirable. [See #9.]

Hearing [no entry]

Vision

Same as #11, with the additional difficulty in seeing whether the manipulation is having the desired result. One alternative is to allow the user to enter commands rather than doing direct manipulation. Ensure keyboard (and hence screen reader) access to these functions.

Speech [no entry]

Cognition

Same as #11. The more complex manipulations may be difficult to remember, especially those modified by SHIFT, ALT, or other keys. Provide alternatives if possible.

13. Recall command names and menu item shortcuts

Mobility [no entry]

Hearing [no entry]

Vision [no entry]

Speech [no entry]

Cognition

Difficulty in remembering and sequencing commands, especially non-mnemonic ones. Fortunately, most important functionality in standard GUIs is available in buttons or menus. Web pages should avoid hiding functionality behind unlabelled graphic buttons. Interactive TV and kiosk applications, which have limited screen real estate and control devices with small numbers of buttons, need to pay special attention to the memorability and usability of the command set. (Setting the time on the VCR is a classic example of a command sequence that is hard to remember.)

14. Enter command names and menu item shortcuts

Mobility

Same as for #9, "Type." StickyKeys, FilterKeys, and adjustable timings are especially important here.

Hearing [no entry]

Vision [See #9.]

Speech [no entry]

Cognition [See #9.]

15. Find and move between data entry fields

Mobility

Same issues as in #9, "Type." Efficient TAB order of fields is important. Accept RETURN or ENTER to submit the form rather than requiring the user to target a button with the mouse. Recognition of voice commands could also be used to jump directly to a given form or field. Web pages typically lack good keyboard access to forms; consider providing a non-mouse method to place the typing cursor in the first field.

Hearing [no entry]

Vision

Same issues in finding the fields as in #6, "Find or see objects." Consistent, efficient navigation schemes are important. Careful attention to the TAB order of fields is needed. Shortcuts for moving between key forms are helpful. Data field labels should be accessible to screen readers. Web pages typically lack good keyboard access to forms; most forms require a mouse click in the first field before allowing users to TAB between fields. Consider placing dummy text in the first field so that screen readers can find it. Accept RETURN or ENTER to submit the form rather than requiring the user to target a button with the mouse.

Speech [no entry]

Cognition [See #9.]

16. Fill in a data entry field

Mobility

Same issues as in #9, "Type," particularly response time issues.

Hearing [no entry]

Vision

Same issues in typing in the fields as in #6, "Find or see objects on screen" and #9. Users should be able to review field contents with a screen reader.

Speech [no entry]

Cognition

Difficulty in remembering valid data values for fields. Minimize errors by methods like: (1) allowing users to choose from a list of valid choices, (2) providing length and format cues for number and date fields, (3) providing examples of valid entries on the screen, (4) providing field-level validation.

17. Speak, or record speech information

Mobility [no entry]

Hearing

Have difficulty hearing, or cannot hear, what they have spoken or recorded. Consider enabling the system to accept and play back text messages, by playing the text through a speech synthesis system.

Vision [no entry]

Speech

Likely to have difficulty recording messages; may prefer to have someone else do it for them. Slow or breathy speech may result in the system detecting silence and so prematurely shutting off recording. Consider adjusting the detection mechanism, or requiring a keypress from the user to terminate recording.

Cognition

Planning voice recordings may be difficult. Ability to erase and re-record may help.

Consider enabling the system to accept and play back text messages, by playing the text through a speech synthesis system.

18. Speak recognized digits, names, or words

Mobility

People who move the microphone, hold it inconsistently while speaking, or move around while speaking may have higher rejection rate.

Hearing

Some people with hearing impairments may be rejected by the recognizer more frequently, since the way they learned to speak may have been affected by their hearing impairment.

Because of the hearing impairment, it's difficult or impossible for these users to hear the confirmation that their utterance has been recognized. Provide a visual confirmation as well.

Vision [no entry]

Speech

Speaker independent voice recognition systems would reject many of these users' utterances. Slow or breathy speech may result in the system detecting silence and so prematurely shutting off recording. Consider adjusting the detection mechanism, or requiring a keypress from the user to terminate recording.

Cognition

Speaking digits in accurate order may be difficult. Ability to edit digit strings or ability to cancel and reenter strings before dialing may help.

19. Hear speech information

Mobility [no entry]

Hearing

Same issues as in #5, "Hear cueing and warning beeps." There is less control, however, over pitch and volume of naturally occurring speech.

QuickTime™ movies can be captioned. TV video should be closed captioned.

Vision [no entry]

Speech [no entry]

Cognition

To allow users to understand speech information at their own pace, provide methods for pausing, rewinding, and replaying it.

20. Set user profile options

Mobility

As in #9, minimize effect of timing and timeouts on what the interface does. Allow users to proceed at their own speed as much as practical. Also allow users to adjust the time interval for responses or to have a non-time-dependent input method.

Ensure that the product is accessible "out of the box." Ensure that the user doesn't have to ask someone else to start it up and adjust timing parameters to make it usable. Microsoft's Windows 95® default installation of accessibility features is an example here.

Hearing [no entry]

Vision

Ensure that the product is accessible "out of the box." Ensure that the user doesn't have to ask someone else to start it up and adjust the application or the screen reader to make it usable.

Provide audio feedback (or screen reader access to text feedback) on which options have been set.

Speech [no entry]

Cognition

As in any system, provide a reasonable initial set of defaults, rather than requiring the person to customize the application. Provide a way to re-establish these defaults.

21. Access documentation, help, or training materials

Mobility

Some people with physical impairments cannot handle printed documentation. Manuals and other documentation need to be available in electronic or audio form.

Hearing

Any training information provided in audio form will need to be available in alternative formats.

Caption training videotapes.

TTY access to help desk staff is needed. TTY access to help line IVRs is desirable [see also #1, "Find out about the product"].

Consider having a well-publicized single voice/TTY number for users to request materials.

Vision

For printed documentation, people with low vision have many of the same issues with type size, contrast, and color as in #6, "Find or see objects" and #7, "Read text."

Provide customer materials in alternate formats, such as large print, Braille, audio tape, and electronic formats. Also consider design of documentation so that it is "scanner/ OCR friendly" (specific recommendations are available). All graphical information in documentation should also be described in text.

Consider Audio Description for training videos.

Speech

Provide alternatives to speaking with help desk representatives. [See #1.]

Cognition

As in all aspects of the product, it's important to keep descriptions simple and clear. Highlighting key information and providing step-by-step instructions are helpful. Use visual examples (diagrams, icons, drawings) as well as text descriptions.

Provide quick reference cards for essential features.

Consider having a well-publicized single voice/TTY number for users to request materials.

22. Insert or eject disks, cards, or other media

Mobility

Difficulty in grasping object, reaching the slot, orienting object to slot. Fragile objects may be damaged during attempt. Difficulty in meeting time constraints for inserting, removing, or swiping an object.

Use doors which push to spring open or which have open handles or levers. Beveled slots facilitate insertion of media.

Media need to be rugged and preferably "hard cased" to accept light clamping. 3.5" disks are a good example. Media and drives should be self-guiding, loading and unloading from the front by pushbutton or software ejection. Devices that eject items 1" and preferably 2" facilitate grasping with fists or tools.

Hearing

Provide visual feedback of status of inserted objects. Support ShowSounds. See also #5, "Hear cueing and warning beeps."

Vision

Difficulty in determining proper orientation or alignment for insertion. Mark orientation of media and receptacle tactually as well as visually. Again, the clipped corner on the 3.5" disk is a good example of marking the orientation. 3.5" drives are also constructed so that it is not possible to fully insert the disk incorrectly.

Braille and/or raised graphics can help identify and orient objects.

Color and shape coding help distinguish similar parts for people with low vision.

Speech [no entry]

Cognition

Use of smart cards may reduce need to memorize access sequences; can also provide customization automatically.

Object orientation and receptacle need to be clearly marked. Even better, ensure that object can't be inserted improperly (again, 3.5" disks are an example).

May be some difficulty with unprompted sequences for inserting and using the card.

23. Plug in auxiliary equipment (CD drives, PC cards, phone lines)

Mobility

Same difficulties in reaching, orienting, and grasping items as in #22, "Insert or eject media." Also, jacks for equipment may be difficult to reach. Make jacks easy to reach. Consider connectors that can be inserted in any orientation, such as headphone jacks. Consider infrared links instead of wires and hard connectors.

Hearing [no entry]

Vision

Difficulties in finding location to plug in or install equipment similar to #22. Difficulties in identifying what jacks are available and in orienting connectors correctly to the appropriate jacks. Need to mark identity and orientation of connectors tactually, provide unique connector/jack combinations where appropriate, and ensure that jacks are electrically safe to explore by touch. Also consider infrared links.

Braille and/or raised graphics can help identify and orient objects for setup.

Color and shape coding help distinguish similar parts for people with low vision.

Speech

May be using a communication aid, a touch-sensitive or keyboard-driven device that allow the user to select words or phrases and have them spoken aloud through speech synthesis. Consider ways to link output from these devices, either by wires or by infrared.

Cognition

Difficulty in determining sequence of events. Difficulty in getting device's plug in correct orientation. Again, consider connectors that can be inserted in any orientation, or infrared links. Take advantage of color and shape coding to distinguish similar parts. Simplify setup.


References

This guide draws on work done at the Trace Center at the University of Wisconsin, which specializes in accessibility issues and solutions. In particular, the following sets of guidelines were used:

Accessible design of consumer products: Guidelines for the design of consumer products to increase their accessibility to persons with disabilities or who are aging. Vanderheiden, G. C., & Vanderheiden, K. R., Compilers (1991). Report #27 - 1.

Considerations 4.2: Results of the Industry/Government Cooperative Effort on computer accessibility for disabled persons. Vanderheiden, G. C. & Lee, C. C., Coord. (1988). Report #28 - 1.

Design of HTML pages to increase their accessibility to users with disabilities: Strategies for today and tomorrow. Version 6.6. Vanderheiden, G. C., Chisholm, W. A., & Ewers, N. (1996). Available at http://trace.wisc.edu/TEXT/GUIDELNS/HTMLGIDE/htmlgide.html.

A compendium of information on accessible design of Web browsers and Web content is available at http://trace.wisc.edu/world/web/index.html.

Microsoft guidelines for accessible design are at http://www.microsoft.com/win32dev/guidelns/msdnaces.htm

Microsoft's overview of accessibility support is at http://www.microsoft.com/windows/enable/default.htm

Apple Macintosh™ user interface guidelines, including universal design, are at http://dev.info.apple.com/hihome.html

Information on Macintosh disability resources is at http://www2.apple.com/disability/disability_home.html

The use of the grid was derived - indirectly - from the work of COST-219, a European body investigating accessibility:

Use of telecommunications: The needs of people with disabilities. Frederiksen, J., Martin, M., Puig, R., & von Tetzchner, S., Eds. (1989). Madrid: Fundesco. Available at ftp://ftp.esat.kuleuven.ac.be/pub/COST219/USE89/.

Thanks to Jim Tobias of Inclusive Technologies for comments on an earlier draft.


Glossary

API

Application Program Interface. A generic term for any language and format used by one program to help it communicate with another program.

Audio description

An additional narration that describes the action in movies, videos, TV, or live performance. A different narrator's voice is used to distinguish the action from the dialog. Audio description is used by people who are blind or who have low vision.

Closed captioning

A text overlay on movies, videos, or TV programs that displays all spoken dialog and sound effects. Closed captioning is invisible until the user chooses to display it. Open captioning, which is less common, is always displayed. Captioning is used by people who are deaf or who are hard of hearing.

GUI

Graphical User Interface. Most commonly refers to a windowed, iconic interface style supporting both mouse and keyboard access, such as the Apple Macintosh™ style and the Microsoft® Windows® style. Other graphical interfaces share many of the same accessibility problems, such as graphical interfaces for kiosks and for interactive TV services.

HTML

HyperText Markup Language. The textual code that produces a World Wide Web document. Specifies the layout of text (headers, paragraphs, bullets), contains references to non-text elements (graphics, movies), and provides hyperlinks between documents.

IVR

Interactive Voice Response system. Voice mail is an example of an IVR system. Customers use a telephone keypad to interact with an information service. The service typically provides spoken prompts and audio feedback. IVRs are being extended to accept speech input and to work with TTYs.

OCR

Optical Character Recognition. Useful to help people with visual impairments read printed documentation. When a document page is scanned into a computer, it is first stored as graphics - patterns of white and black on the page. OCR software finds letters in the image and converts the document to screen-readable, editable text.

Relay service

Enables users who have hearing or speech disabilities to place calls to and receive calls from hearing people. There are several variations. Most commonly, typed TTY messages are transmitted to a Communication Assistant who voices them to hearing persons. Hearing persons' messages are voiced to the Communication Assistant who relays them to the TTY printout or display. TTY users may also choose to speak for themselves but get responses via TTY ("Voice Carryover"), or listen for themselves but send responses via TTY ("Hearing Carryover"). Finally, speech relay services may also be used by customers with speech impairments who do not have a TTY. In this case, the Communication Assistant simply re-voices what the person with a speech impairment says.

Screen reader

An application used by people who are blind or who have low vision. It builds an off-screen model of windows, menus, dialog boxes, and objects on the screen. Users can scan this representation, which is read aloud via text-to-speech output. They can then randomly access menus, data entry fields, and other screen objects. Keyboards, not mice, are typically used with screen readers; it is possible to move the mouse around the screen and have the names of objects read aloud, but that is an error-prone and time-consuming method of finding information.

TDD

Telecommunications Device for the Deaf. More commonly known as TTY.

TTY

Text telephones having a keyboard and display. TTY users type messages to each other rather than speaking. When a voice telephone user is having a conversation with a TTY user, a relay service operator ("Communication Assistant") provides the translation between voice and text. TTYs are also known as TDDs.

Further information

This guide was written by Ellen Francik of Pacific Bell's Human Factors Engineering group. Questions or comments can be directed to her at 2600 Camino Ramon, Rm. 3E050H, San Ramon, CA 94583. Electronic mail: epfran1@pacbell.com. Phone: (510) 867-8662.

Human Factors Engineering also provides usability and universal design services to Pacific Bell and to other Pacific Telesis companies.

Pacific Bell's Deaf and Disabled Market Group:

Contact Marcia Straehley, Director, at 2150 Shattuck Avenue, Suite 200, Berkeley, CA 94704. Phone: (510) 704-3650.



trace.wisc.edu
This document is hosted on the Trace R&D Center Web site. Please visit our home page for the latest information about Designing a More Usable World - for All.