designing 4 disabilities
TRANSCRIPT
Presented on Friday 11th September, 2009
Designing for Disabilities
Richard J. Appleyard, PhDClinical Assistant Professor, Medical
Informatics, OHSUBusiness Technology Manager, City of Portland
Holistic Technology Guru
My Background
• Webmaster, Oregon Health & Science University, www.ohsu.edu , [email protected]
• Director Disability Informatics, Oregon Institute on Disability & Development, www.oidd.org
• Web Development Instructor, PSU • Holistic Technology Guru, www.enablingit.com ,
[email protected] • Business Technology Manager, Bureau of
Development Services, City of Portland, www.portlandonline.com/bds
Herding Cats
Acronym Soup
• If YDNUTA,
• then AMAQ
Acronym Soup
• If You Do Not Understand The Acronym
• then Ask Me A Question
Overview
• What are disabilities?• Why care about them?• How do I design technology for people
with disabilities?• How do I design websites for people
with disabilities?• What tools can I use in accessible Web
design
Defining Disability
What are disabilities?
Audience Poll
• How many people have a disability?
• How many people – have glasses/contacts?– have had corrective
eye-surgery?
World Health Organization
• “An impairment is any loss or abnormality of psychological, physiological or anatomical structure or function; a disability is any restriction or lack (resulting from an impairment) of ability to perform an activity in the manner or within the range considered normal for a human being; a handicap is a disadvantage for a given individual, resulting from an impairment or a disability, that prevents the fulfillment of a role that is considered normal (depending on age, sex and social and cultural factors) for that individual”
Person:Environment
Prevalence of Disability
DisabilityEstimated Size (US population)
Source
Self-reported disability (unable to perform ADLs)
~50 million (20%); ~14 million > 65y (42%)
U.S. Census Bureau, 2000http://www.census.gov/main/www/
cen2000.html
Visual Impairment 8.1 million (3.2%)1.3 million legally blind
5 million > 65y(1 million severely)
U.S. Census Bureau, 1994-95; U.S. National Center for Health Statistics, 1994,1995
Hearing Impairment ~20 million (8.6%),
~30 million > 65y (29%)
U.S. National Center for Health Statistics. Vital Health Statistics, 1990-91
Cognitive Disabilities (MR, Brain Injury, Dementia / Alzheimer’s)
~15 million (~7%)
~20 million (8.6%), including Mental Health
U.S. Census Bureau, 1990; NIH, 1998; BIA; Alzheimer's Association, 2003; Arc, 2004
Disability Informatics
“The discipline of science that researches the development and use of information, telecommunications and information technology, such that benefits may be derived from that information by the users, and more specifically people with disabilities”
Rehabilitation
Physiatry
AAC
Special Education
Informatics
Medical
Public Health
Consumer Health
Bioinformatics
Assistive Technology
Interface of Fields
Disability Informatics
Importance of Accessibility
Why Care?
Web Accessibility
"The power of the Web is in its universality. Access by everyone
regardless of disability is an essential aspect."
-Tim Berners-Lee, W3C Director, inventor of the World Wide Web
Inverse information law
“…access to appropriate information is particularly difficult
for those who need it most.”
–Gunther Eysenbach (BMJ, 2000)
Digital Divide - Computer UseP
erce
ntag
e of
w
orki
ng a
ge a
dults
http://www.microsoft.com/enable/research/ (2003)
Adapted from online article in Digital Web magazine, RIP!
Excuses for Lack of Accessibility
• It’s not something [we] want to think about• It is not really required (reasonable accommodation) • It’s the law but there’s none to follow• There is no immediate benefit• It’s just a technical problem• It’s too much work (reasonable accommodation) • It seems like a party pooper• Nobody complains / No students with disabilities• There is no leader to follow
Web Accessibility Laws
• Rehabilitation Act (1973, 1998) – Section 508 (June 25, 2001) requires
federal agencies Web sites to be accessible
• Americans with Disabilities Act (1985) – Title I: Employment– Title II: State/Local Government activities– Title III: Public Accommodations
ADA Legal Cases
• Tyler v. City of Manhattan [student] (1994)• Hooks vs. OKBridge [cognitive] (1999)• Natl Federation of the Blind vs. AOL [Title III] (2000)• The UC Davis and UC Berkeley Settlement
[deaf students] (1999)• Southwest Airlines vs. Robert Gumson and Southwest
Airlines vs Access Now [blind user] (2002)• Martin vs. MARTA (Metropolitan Atlanta Rapid Transit
Authority) [Title II] (2002)• Spitzer Agreement / Travel Web sites [Title III] (2004)• National Federation of the Blind (NFB) vs. Target (2006)
Web Developer Accessibility Survey
• 55% of Web developers do not use Web development standards
• Of the 45% that do,Only 20% use Web Accessibility guidelines or requirements
still a lack of awareness of the importance of Universal Web Design
– Internet Professionals NW, May 2005
Designing Accessible Technology
How do I design technology for people with disabilities?
Universal Design
“The design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design”
(The Center for Universal Design, NC State University)
http://www.design.ncsu.edu/cud/about_ud/about_ud.htm
Principles of Universal Design
• Physical Environment– Equitable Use– Flexibility in Use– Simple and Intuitive Use– Perceptible Information– Tolerance for Error– Low Physical Effort– Size and Space for
Approach and Use
• Computer/Web Environment– Equitable Use– Flexibility in Use– Simple and Intuitive Use– Perceptible Information– Tolerance for Error– Low Physical Effort– Independence of computer
platform / user agent or device / assistive technology
Assistive Technology
“any item, piece of equipment, or product system, whether acquired commercially, modified, or customized, that is used to increase, maintain, or improve functional capabilities of individuals with disabilities” – AT Act of 1998 (Section 508)
Computer Assistive Technology (AT)
• Input– Alternative, adaptive
keyboards– Touch screens, tablets– Joystick, Trackball,
Switch– Eye/Head tracking– Speech recognition
[On/Off] Switch On-screen Keyboard
Computer Assistive Technology (AT)
• Output– Screen
magnification– Print/refreshable
braille– Speech synthesis
Accessible Web Design
How do I design websites for people with disabilities?
Web HistoryAccessibility Perspective
• <1990 – Terminal (TTY), Dial-up (Modems)• 1990-5 Graphical User Interface (GUI)
Images without text description Barrier to people who are blind
• 2000-5 Dial-up Broadband (Cable, DSL) Video without text description Barrier to people who are deaf
• 2005-present Media Convergence Rich, complex Web interfaces Barrier to people with cognitive disabilities
• 2008-present Mobile Web Smartphones (Browser diversity)
Principles of Universal Web Design
Web Content Accessibility Guidelines(v.2, due Spring 2005….delivered December 2008!)
1. Perceivable. Ensure that all intended function and information can be presented in form(s) that can be perceived by any user - except those aspects that cannot be expressed in words.
2. Operable. Ensure that the interface elements in the content are operable by any user.
3. Navigable. Facilitate content orientation and navigation.4. Understandable. Make it as easy as possible to understand the
content and controls.5. Robust. Use Web technologies that maximize the ability of the
content to work with current and future accessibility technologies and user agents.
http://www.w3c.org/WAI/
Visual Impairments
• Text is preferred to images
• Adjustable font preferred to fixed font
• Alternate text for images / visual content
• Adjusting for linear processing– nature of text-to-speech browsers (JAWS)
• Use CSS for layout instead of Tables
• Accessible Tables & Forms
Color Blindness
• Affects 8 to 12% of males of European origin and about half a percent of females
• Avoid using color to indicate something specific on a Web page
• Avoid using red and green colors together• View Web pages desaturated (in grayscale)
in order to determine their effectiveness
Color Blindness
• Affects 8 to 12% of males of European origin and about half a percent of females
• Avoid using color to indicate something specific on a Web page
• Avoid using red and green colors together• View Web pages desaturated (in grayscale)
in order to determine their effectiveness
Hearing Impairments
• Initially not as badly impacted since the Web is a very visual environment
• However, the Web is increasingly rich with multimedia and video with audio tracks– Transcripts of audio and sub-titles to video are
needed to make them accessible (Section 508)
– This will also be of benefit to
• Speakers of other languages
• Internet devices that are not sound equipped.
Mobility Impairments
• Many users have difficulty using the mouse and keyboard
• Addressed by assistive technology (AT) hardware and software
• It is worth being sensitive to mobility issues– avoid long navigation sections before main content,
provide a “skip to main content” link – avoid image maps with extremely fine positioning, – always ensure that Web page elements can be
navigated by keyboard (such as client-side image maps, Java, ActiveX)
Cognitive Impairments
• There are many types of cognitive impairments ranging from– severe, e.g., Alzheimer’s– mild reading and learning disorders
• Few accessibility guidelines for cognitive disabilities – Lack of user interface research and empirical data
• Benefit from general “usable” site design– maintaining the content at a 6-8 grade school level – the use of icons graphics and multimedia that aids
in understandinghttp://www.webaim.org/articles/cognitive/
The Web Challenge
• Accessibility requirements for one group of users often conflicts with those for another,– Sensory disability, Cellphone, Search
Engineemphasis on text-based
– Cognitive or Learning disability, low literacyemphasis on
image/video/multimedia-based
Accessible Web site
http://www.webaim.org/
Inaccessible Web site
http://www.fluwatch.com/ (RIP!)
Web Design Tools
What tools can I use in accessible Web design?
HTML Validation
• Many checks can be done without tools– Turn off images, sounds, and style sheets– Test site with a text browser/alternate devices– Consult users with disabilities– Set monitor to black & white
But Watch Out!• Many checks cannot be performed by tools
– Utility of ALT text
Validation Tools
• Built-in to many development tools– e.g., Dreamweaver
• W3C HTML validator– http://validator.w3.org/
• WAVE (WebAIM) validator FREE– http://wave.webaim.org/
• A-Prompt (W3C) FREE– http://www.w3.org/People/Raggett/tidy/
• Bobby (Watchfire) – http://www.cast.org/products/Bobby/
Web Browser Toolbars
• Web Developer Extension (Firefox)http://chrispederick.com/work/firefox/webdeveloper/
• Web Accessibility Toolbar (IE)http://www.visionaustralia.org.au/ais/toolbar/
JAWS
• Full interface control – Windows OS
– Many applications
• Version 7.0
• Expensive– $900 - $1300
• Demo version available– 40 minute limit
http://www.freedomscientific.com/fs_products/software_jaws.asp
Perform Usability testing
• Involve users early and often• Use an iterative process
– design, test, design, test, etc.
• Test early and often– The earlier usability issues are
discovered…the easier and cheaper it is to fix them
• Usability tests do not have to have huge samples of participants – using 5 testers -> 85% of the usability problems– using 1 tester with a screen reader -> 100% of the
accessibility problems
Final Thoughts
• Accessibility is an approach to design, not a stamp of approval
• Separating content from layout is an essential strategy for accessible design
• Emerging standards continue to make the Web accessible
• Many competing standards and different ideas about “accessibility”
• Avoid retrofitting by planning for accessibility, awareness is the first and most critical step
Building Airplanes
Additional Resources
• W3C Web Accessibility Initiative, www.w3c.org/WAI
• WebAIM (Accessibility in Mind), www.webaim.org
• Information Technology Technical Assistance and Training Center (ITTATC), www.ittatc.org
• National Center on Accessible Information Technology in Education (ACCESS-IT), www.washington.edu/accessit
• National Center for Accessible Media, ncam.wgbh.org – Accessible Digital Media, ncam.wgbh.org/publications/adm
• Regional ADA Centers: 1-800-949-4232
• Useit.com (Nielsen), http://www.useit.com/alertbox/9706b.html
• Google, www.google.com
Thank you!
Richard Appleyard