Word (.doc) format

CHI 2007 Course Notes

Web Usability

for

Assistive Technology

Presented at CHI 2007, San Jose, CA

May 1, 2007

by

Caroline Boyden [email protected]

and

Lucia [email protected]

University of CaliforniaBerkeley, CA 94720

Copyright is held by the author/owner(s).CHI 2007, April 28-May 3, 2007, San Jose, California, USA.

ACM 07/0004.

CHI 2007 Course Notes Caroline Boyden and Lucia Grecoi

Table of Contents

Instructor biographies iv

Agenda v

Objectives of the course v

Introduction 1

Course notes, part 1 1

Course notes, part 2 6

Bibliography 11

Resources 13

CHI 2007 Course Notes Caroline Boyden and Lucia Grecoiii

Instructor Biographies

Caroline Boyden and Lucia Greco are members of the WebAccess working group at UC Berkeley. The group focuses on technology, education, advocacy, and policy for website developers and users.

Caroline Boyden

Caroline Boyden is a designer and developer on the College of Letters & Science Computer Resources web team. She has ten years of experience in website and web application design, with an emphasis on accessibility.

Lucia Greco

Lucia Greco is the Assistive Technology Specialist for the Disabled Students Program. She has provided disability awareness and technology training to individuals, and organizations such as the City of Oakland and the Bay Area Rapid Transit District.

CHI 2007 Course Notes Caroline Boyden and Lucia Grecoiv

Agenda

Part 1

1. Introduction and background.2. Overview of legal and market conditions affecting web accessibility in the

U.S.3. Review of types of disabilities and their effects on web user experience.

Perceptual, mobility, cognitive, and other impairments.4. Demonstration of assistive technologies for the web. Screenreaders;

literacy software; system settings; input devices.5. Common ground between accessibility modifications and general usability

improvement. Benefits of accessibility for all users.6. Questions and answers. Discussion.

Break

Part 2

1. The standards: Section 508 and WCAG 1.0 checklists. WCAG 2.0 and surrounding controversy.

2. Beyond the standards: Tips and guidelines for development. A collection of cheat sheets and best practices.

3. Automated testing tools: from free and web-based to enterprise-level.4. Developer tests and tools: browser extensions and plugins.5. End-user testing.6. Accessibility for Web 2.0. Live review of an Ajax-based web application.7. Questions and answers. Discussion.

Objectives of the course

After completing the course, attendees will be able to:

Understand the legal and market conditions that affect web accessibility; Understand the major effects of perceptual, mobility, and cognitive

disabilities on web user experience; Know the benefits and limitations of assistive technologies; Recognize the advantages of accessibility enhancements for all users; Determine the most efficient combination of evaluation methods for their

needs; Use automated, developer, and end-user testing tools and techniques; and Incorporate knowledge of accessibility issues into their projects from the

ground up.

CHI 2007 Course Notes Caroline Boyden and Lucia Grecov

Introduction

Is your website accessible to users of assistive technology? How do you know? This course will provide you with practical knowledge and techniques to understand accessibility, evaluate your sites and applications, and improve user experience.

Attendees will learn:

How perceptual, mobility, and cognitive disabilities affect user experience

What assistive technologies are available, and how they work

Strengths and weaknesses of different accessibility testing methods

Tools and techniques anyone can use to evaluate and improve their projects

Course Notes, Part 1

Legal and market conditions in the U.S.

Legal landscape

o Section 508 of the Rehabilitation Act of 1973 (as amended 1998) guarantees access to electronic and information technology procured by federal agencies. The standards are based WCAG 1.0.

o Section 504 of the Rehabilitation Act requires any organization receiving U.S. federal government funding to ensure accessibility to all programs.

o ADA (Americans with Disabilities Act) of 1990 applies to “places of public accommodation.” It was enacted before the internet boom, and has not yet been interpreted to apply to websites.

o In response to a lawsuit, the U.S. District Court for South Florida held that the ADA did not apply to Southwest.com because the ADA only applies to physical places of public accommodation. An appeals court declined to take the case.

o New York’s Attorney General argued that ADA does apply to websites in a complaint against Ramada.com and Priceline.com. The companies settled out of court in 2004, agreeing to comply with WCAG accessibility standards.

CHI 2007 Course Notes Caroline Boyden and Lucia Greco1

o The NFB (and a Berkeley student) sued Target.com under Title III of the ADA. The suit states that Target.com is a service of Target stores, which are physical places of public accommodation. In September 2006, the U.S. District Court for Northern California ruled that the case could proceed under the ADA.

Structured negotiations

o Rather than relying on the possibly shaky ground of the ADA for a lawsuit, disability advocates have had success in direct negotiations with major corporations to improve websites and other technologies.

o In the financial services industry, major banks such as Bank of America, BankOne (now Chase), and Washington Mutual have signed legally binding agreements to comply with Priority 1 and 2 of the WCAG.

o Agreements also apply to talking ATMs, tactile point-of-sale devices, and other technologies.

Demographics and market conditions

o Census data: 50 million Americans live with disabilities. Seventy-six million are baby boomers, now beginning to hit retirement age.

o Microsoft commissioned “The Market for Accessible Technology,” a survey of working-age adults (18 to 64) focused on computer use by persons with disabilities. The survey included task-based questions about specific difficulties, so it captured users who do not self-identify as having a disability. The survey found:

Many trends are converging to increase the number of people affected: the U.S. population is aging; impairments increase in number and severity with age; the average lifespan is increasing; people are delaying retirement; generational waves of computer adoption mean the percentage of population using computers will continue to increase.

Forty percent of computer-using adults are likely to benefit from assistive technology; 17% are very likely.

o Effects of technology on incidence of disabilities

Life-saving medical advances mean more people are living longer with disabilities.

CHI 2007 Course Notes Caroline Boyden and Lucia Greco2

Increased computer use among all ages means more potential for RSI.

More information:

Lainey Feingold, “Web Accessibility and the Law: Recent Legal Developments and Advocacy Strategies,” California State University-Northridge, Technology And Persons With Disabilities Conference, 2005http://www.csun.edu/cod/conf/2005/proceedings/2116.htm

Section 508 of the 1998 amendments to the 1973 Rehabilitation Act, 29 U.S.C. 794(d)http://www.access-board.gov/508.htmhttp://www.section508.gov/

Americans with Disabilities Acthttp://ada.gov/

Southwest Airlines lawsuithttp://caselaw.lp.findlaw.com/data2/circs/11th/0216163p.pdf

Priceline.com and Ramada.com settlementhttp://www.oag.state.ny.us/press/2004/aug/aug19a_04.html

Target.com lawsuithttp://www.jimthatcher.com/law-target.htmhttp://www.dralegal.org/cases/private_business/nfb_v_target.php

“The Market for Accessible Technology—The Wide Range of Abilities and Its Impact on Computer Use”http://www.microsoft.com/enable/research/phase1.aspx

Types of disabilities and their effects on web user experience

Hearing impairments

o Examples: deafness, age-related hearing loss

o The syntax of American Sign Language is not at all similar to spoken and written English; users who learn ASL first effectively speak English as a second language.

o Closed-captioning in web multimedia is accessible to deaf-blind users with Braille displays.

Mobility and physical impairments

o Examples: Repetitive stress injuries, cerebral palsy, quadriplegia.

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o Users who cannot control a mouse can tab through web pages element by element; if an element is not focusable by the keyboard, it is inaccessible.

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o Users with extremely limited movement may have a switch device with a virtual keyboard; to type, the software cycles through every key and the user activates the switch when the appropriate key is in focus.

o Voice input software to control web browsers navigates one element at a time, similar to keyboard-only navigation. Users depend on consistent, concise labeling for efficient browsing. Heavy use of voice input can cause damage to vocal cords.

Cognitive impairments

o Examples: ADD, dyslexia, learning disabilities, Asperger syndrome.

o Nonverbal cues (color, typography) increase understanding when used consistently.

o Literacy software assists users by highlighting and reading aloud at the same time.

Visual impairments

o Examples: Blindness, low vision (contrast or peripheral vision), color deficiency, age-related vision changes

o Users may alter color combinations to increase contrast, reduce glare, or reduce distraction. Individual color scheme preferences vary widely depending on the nature and severity of the disability.

o Small print becomes increasingly difficult to read with age. Older users and low-vision users will decrease screen resolution or increase default text size.

o Magnification software can make elements up to 50 times larger. Users lose the context of elements surrounding what they magnified.

o Screenreaders work by intercepting the information sent from the application to the video driver. Output can be rendered as speech or as Braille on a refreshable display.

o A screenreader requires that the user construct a mental model of a screen by listening to its parts one at a time. Proficient users can skip back and forth easily.

Other impairments

o Chronic fatigue, seizure disorders

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Assistive technologies demonstration and discussion

Screenreaders

o JAWS for Windows: http://www.freedomscientific.com/fs_products/JAWS_HQ.asp

o VoiceOver for Mac: http://www.apple.com/accessibility/voiceover/

Literacy software

o WYNN for Windows: http://www.freedomscientific.com/LSG/products/wynn.asp

System settings

o Mac: http://www.apple.com/accessibility/

o Windows: http://www.microsoft.com/enable/products/windowsxp/default.aspx

Alternative input: Keyboard-only navigation

Common ground between accessibility and general usability; other benefits

Accessibility is a form of usability. Just as curb cuts improved life for many in addition to wheelchair users, web accessibility modifications also benefit non-disabled users.

Google is blind. Since search engines have not (yet!) come up with anything that can interpret images and media the way a sighted person does, they rely on the text content of a site to index and link it correctly.

Workplace and public-access computers are mute. Corporate workstations and public-access computers often either have no capacity for sound, or have the sound turned off. Computer users in shared offices or public spaces may keep their sound low or off to avoid disturbing others. Captions and transcripts make audio content available in these contexts.

Preventing and accommodating RSI is a good thing. Keyboard navigation increases efficiency and decreases unnecessary hand movements.

Semantic markup requires up-front thinking about page. Good information architecture leads to an accessible, usable site.

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Appropriate contrast increases readability for all, from the elderly to the visually-impaired.

Course Notes, Part 2

The standards

Section 508

o Standards: http://www.section508.gov/index.cfm?FuseAction=Content&ID=12

o Commentary: http://webaim.org/standards/508/checklist.php

WCAG 1.0

o Standards: http://www.w3.org/TR/WAI-WEBCONTENT/

o Techniques: http://www.w3.org/TR/WAI-WEBCONTENT-TECHS/

WCAG 2.0

o Standards: http://www.w3.org/TR/WCAG20/complete.html

o Commentary: http://www.w3.org/TR/UNDERSTANDING-WCAG20/

o Techniques: http://www.w3.org/TR/WCAG20-TECHS/

o Controversy: http://alistapart.com/articles/tohellwithwcag2/

If a site isn't compliant with one of these sets of standards, that guarantees it's not accessible. If it is compliant, however, that doesn't guarantee it is accessible.

Beyond the standards

Top ten tips and fixes, as hammered out over a year and a half of website reviews:

1. Skip navigation links. Particularly useful for screenreader and keyboard-only users. Skip links should be visible. Expands on section 508 rule (o).

2. Heading elements, used correctly.

3. CSS for layout and typography. Flexible, semantic.

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4. Images: Use sensible ALT text, left empty if the image is purely decorative. Expands on Section 508 rule (a) / WCAG 1.0 checkpoint 1.1

5. Color: Use sufficient contrast, and do not rely on color alone to convey meaning. Expands on Section 508 rule (c) / WCAG 1.0 checkpoint 2.1

6. Create unique names for links, with the most useful information at the beginning of the link text.

7. Use “Go” buttons with drop-down lists used for navigation. Anything that acts onChange will trap screenreader and keyboard-only users.

8. Label and order form fields. Unlabeled or mislabeled form fields are a killer for screenreader users on any interactive site. Form instructions should appear before the fields they apply to. Expands on Section 508 rule (n).

9. Manage tab order for efficient keyboarding.

10.No more text-only alternatives. Don't maintain a mirror (even an automatically-generated one). Text-only sites do nothing for users with mobility impairments, and are worse for users with learning disabilities and other cognitive impairments. Makes moot Section 508 rule (k) / WCAG 1.0 checkpoint 11.4.

More cheat sheets:

Jakob Nielsen's report on accessibility: http://www.nngroup.com/reports/accessibility/

National Cancer Institute recommendations: http://portal.acm.org/citation.cfm?doid=947226.947227; or with additional figures: http://redish.net/content/papers/interactions.html

Dive Into Accessibility's tips by type of disability: http://diveintoaccessibility.org/by_disability.html

The W3C's short list: http://www.w3.org/WAI/References/QuickTips/

Automated testing tools

Validate first: pick a DOCTYPE and stick to it. Browser differences are bad enough with clean, valid code. Anything worse, and the problems multiply.

Free and web-based tools

CHI 2007 Course Notes Caroline Boyden and Lucia Greco8

o Cynthia Says. http://www.cynthiasays.com/ The Firefox Web Developer Toolbar uses this site by default. It validates to either Section 508 or WCAG, with options on level of warnings. Results are in the form of a tabular report, with a pass/fail note at the top.

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o WebXact. http://webxact.watchfire.com/ScanForm.aspx This service is a descendant of Bobby, one of the first online accessibility tools. It checks for compliance with WCAG by default; the advanced options allow checking against Section 508. Results are more detailed and warnings are easier to interpret.

o WAVE. http://www.wave.webaim.org/ The WAVE doesn't produce a report or a pass/fail mark. It redisplays the page with icons inserted whenever there's an error (red), a warning (yellow), or an accessibility feature (green). It also inserts icons pointing out structural markup features such as DIVs, lists, tables, etc. Good for users of WYSIWYG tools such as Dreamweaver.

Enterprise-level tools

o Jim Thatcher (http://www.jimthatcher.com/testing.htm) evaluated six automated testing tools using 40 criteria. Two tools, Deque's Ramp Ascend (http://www.deque.com/products/ramp/index.php) and Parasoft's WebKing (http://parasoft.com/jsp/products/home.jsp?product=WebKing), were the tops in criteria passed, with 38 and 34 respectively.

o Ramp Ascend will spider an entire site and report violations of Section 508, WCAG 1.0, or both at once. It can automatically repair many common violations, and guides users through some checkpoints that require judgment.

Automated testing tools are good for speed, efficiency, and catching oversights and stupid mistakes.

More information:

W3C's HTML validator: http://validator.w3.org/ W3C's CSS validator: http://jigsaw.w3.org/css-validator/

Developer testing tools

Firefox Web Developer Toolbar: https://addons.mozilla.org/firefox/60/

Firefox Web Accessibility Extension: https://addons.mozilla.org/firefox/1891/

IE Accessibility Toolbar: http://www.visionaustralia.org.au/info.aspx?page=614

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Developer tests, primary

1. Images off

2. Keyboard only, no mouse

3. Mouse only, no keyboard

4. Stylesheets off

5. Javascript off

6. Colorblind simulation – see Vischeck, http://www.vischeck.com/ and Juicy Studio, http://juicystudio.com/services/colourcontrast.php

7. Extra-large text sizes

More developer tests

1. Text-only browser – see Lynx, http://lynx.browser.org/

2. CSS on, Javascript off; Javascript on, CSS off (these last two are more important if you're doing Ajax or any heavy DOM scripting)

3. High-contrast settings

4. Grayscale monitor

5. Readability testing

More information:

Multiple Firefox installations: http://muffinresearch.co.uk/archives/2006/10/25/run-firefox-20-and-15-side-by-side/

Multiple IE installations: http://tredosoft.com/Multiple_IE

Readability testing: http://juicystudio.com/services/readability.php

End-user testing

In a paper presented at CHI 2005 (http://doi.acm.org/10.1145/1054972.1054979), Jennifer Mankoff, Holly Fait, and Tu Tran reported on the relative effectiveness of different testing methods for screenreader accessibility. Their results suggest that of the more "discount" methods, testing by sighted developers using screenreaders is the most effective.

CHI 2007 Course Notes Caroline Boyden and Lucia Greco11

For a screenreader user: average training time to use the software is 40 hours. Approximately one-third of this is devoted to using the screenreader with a browser.

It can be hard to separate problems with the tool (e.g., a screenreader) from problems with the task.

Assistive technology users have vastly different levels of experience with technology and disabilities of varying severity.

Assistive technologies should be tested in the default configuration.

The most commonly-used screenreader customizations are verbosity, speed, spoken punctuation, and typing echo.

Think-aloud, interactive testing with developers and assistive technology users together captures the most useful information. Mankoff, Fait, and Tran’s control group is the best way to test.

Accessibility for Web 2.0

The fundamental things apply.

o Start from a foundation of accessible HTML; then consider your interactivity.

The two overwhelming issues for Ajax sites are:

o Informing users that page content has changed; and

o Providing access to the changed content.

IBM, Mozilla, Freedom Scientific, and others are developing a new accessibility API, IAccessible2, to extend MSAA.

More information:

IAccessible2: http://www-03.ibm.com/press/us/en/pressrelease/20773.wss Joe Clark, “Build Half a Product,”

http://joeclark.org/access/research/ice//iceweb2006-notes.html James Edwards, “AJAX and Screenreaders: When Can it Work?”

http://www.sitepoint.com/article/ajax-screenreaders-work WebAIM, “Accessibility of AJAX Applications,”

http://webaim.org/techniques/ajax/

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Bibliography

“Access Now, Inc. v. Southwest, D. C. Docket No. 02-21734 CV-PAS”, Sept 24, 2004, http://caselaw.lp.findlaw.com/data2/circs/11th/0216163p.pdf

Al Saif, Y., “Install multiple versions of IE on your PC,” Tredosoft, July 11, 2006, http://tredosoft.com/Multiple_IE

“Americans with Disabilities Act Home Page”, US Department of Justice, Decem-ber 20, 2006, http://ada.gov/

Caldwell, B., Chisholm, W., Slatin, J., and Vanderheiden, G., Eds., “Techniques for WCAG 2.0, W3C Working Draft 27 April 2006,” W3C World Wide Web Con-sortium, April 27, 2006, http://www.w3.org/TR/WCAG20-TECHS/

Caldwell, B., Chisholm, W., Slatin, J., and Vanderheiden, G., Eds., “Understand-ing WCAG 2.0 W3C, Working Draft 27 April 2006,” W3C World Wide Web Con-sortium, April 27, 2006, http://www.w3.org/TR/UNDERSTANDING-WCAG20/

Caldwell, B., Chisholm, W., Slatin, J., and Vanderheiden, G., Eds., “Web Content Accessibility Guidelines 2.0, W3C Working Draft 27 April 2006,” W3C World Wide Web Consortium, April 27, 2006, http://www.w3.org/TR/WCAG20/complete.html

Chishom, W., Vanderheiden, G., and Jacobs, I., Eds., “Techniques for Web Con-tent Accessibility Guidelines 1.0, W3C Note 6 November 2000,” W3C World Wide Web Consortium, November 6, 2000, http://www.w3.org/TR/WAI-WEBCONTENT-TECHS/

Chishom, W., Vanderheiden, G., and Jacobs, I., Eds., “Web Content Accessibility Guidelines 1.0, W3C Recommendation 5-May-1999,” W3C World Wide Web Consortium, May 5, 1999, http://www.w3.org/TR/WAI-WEBCONTENT/

Clark, J., “Build Half a Product,” edited speaking notes from a presentation given at Iceweb 2006, Reykjavík, April 28, 2006, posted May 4, 2006, http://joeclark.org/access/research/ice//iceweb2006-notes.html

Clark, J., “To Hell with WCAG 2,” A List Apart, May 23, 2006, http://alistapart.com/articles/tohellwithwcag2/

Colville, S., “Run Firefox 2.0 and 1.5 side by side,” Muffin Research Labs, Octo-ber 5, 2006, http://muffinresearch.co.uk/archives/2006/10/25/run-firefox-20-and-15-side-by-side/

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Coyne, K. P. and Nielsen, J., “Beyond ALT Text: Making the web easy to use for users with disabilities,” Nielsen, Norman Group, October, 2001, Available at: http://www.nngroup.com/reports/accessibility/

Edwards, J., “AJAX and Screenreaders: When Can it Work?” May 5, 2006, http://www.sitepoint.com/article/ajax-screenreaders-work

Feingold, L.,“Web Accessibility and the Law: Recent Legal Developments and Advocacy Strategies,” California State University-Northridge, Technology And Persons With Disabilities Conference, 2005, http://www.csun.edu/cod/conf/2005/proceedings/2116.htm

Fishkind, A., “IBM Helps Disabled Users Get More From Assistive Technology, on More Computer Platforms,” IBM Media Relations, December 14, 2006, http://www-03.ibm.com/press/us/en/pressrelease/20773.wss

Henry, S. L. and Popolizio, P., Eds, “Quick Tips to Make Accessible Web Sites” W3C World Wide Web Consortium, January 2001, http://www.w3.org/WAI/References/QuickTips/

Lemon, G., “Readability Test,” Juicy Studio, United Kingdom, last update 2007, http://juicystudio.com/services/readability.php

Mankoff, J., Fait, H. and Tran, T., “Is your web page accessible?: a comparative study of methods for assessing web page accessibility for the blind,” Conference on Human Factors in Computing Systems, Proceedings of the SIGCHI confer-ence on Human factors in computing systems, Portland, Oregon, 2005, pages: 41 – 50, ACM Press, New York, NY, 2005, Available at: http://portal.acm.org/citation.cfm?doid=1054972.1054979

“The Market for Accessible Technology—The Wide Range of Abilities and Its Im-pact on Computer Use,” Forrester Research, Inc., Cambridge, MA, 2003, http://www.microsoft.com/enable/research/phase1.aspx

“National Federation of the Blind v. Target,” Disability Rights Advocates, Berke-ley, CA, September 7, 2006, http://www.dralegal.org/cases/private_business/nfb_v_target.php

Pilgrim, M., “30 Days To A More Accessible Website,” Dive Into Accessibility, January 2007, http://diveintoaccessibility.org/by_disability.html

“Section 508 of the 1998 amendments to the 1973 Rehabilitation Act 29 U.S.C. 794(d)”,1998, http://www.access-board.gov/508.htmhttp://www.section508.gov/

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“Spitzer Agreement to Make Web Sites Accessible to the Blind and Visually Im-paired,” Office of the New York State Attorney General, August 19, 2004, http://www.oag.state.ny.us/press/2004/aug/aug19a_04.html

Thatcher, J.W., “Accessibility, Law and Target.com”, jimthatcher.com, Austin, TX, 2006, http://www.jimthatcher.com/law-target.htm

Thatcher, J.W., “Web Accessibility Testing,” excerpt from Web Accessibility: Web Standards and Regulatory Complaince, by Thatcher, J et al., Friends of Ed, Berkeley, CA, July, 2006, reprinted by jimthatcher.com, Austin, TX, last update August 2006, http://www.jimthatcher.com/testing.htm

Theofanos, M.F. and Reddish, J., “Bridging the Gap: Between Accessibility and Usability,” Interactions, Vol. 10, Issue 6, p. 36-51, Nov-Dec 2003, ACM Press, New York, NY, 2003, Available at: http://portal.acm.org/citation.cfm?doid=947226.947227

Theofanos, M.F. and Redish, J., “Bridging the Gap: Between Accessibility and Usability,” Author’s version of Theofanos and Redish, reprinted and expanded from Interactions, Vol. 10, Issue 6, p. 36-51, November-December 2003, ACM Press, New York, NY, republished by Redish & Associates, last update 2007, http://redish.net/content/papers/interactions.html

WebAIM, “WebAIM Section 508 Checklist,” last update 2007, http://webaim.org/standards/508/checklist.php

WebAIM, “Accessibility of AJAX Applications,” http://webaim.org/techniques/ajax/

Resources

All course materials and supplemental resources are available online at http://ls.berkeley.edu/cboyden/chi2007/

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