Birkbeck University of LondonBusiness Workshop
Web Accessibility for All Janet Billinge
© 2001-2007 Copyright Janet Billinge Includes some slides derived from Design for All
© Netskills, Quality Internet Training, University of Newcastle
Topics
Disability and the web Disability types Design considerations
Web standards and the law Strategies
Disability and the web
8.5 million adults registered disabled in the UK 14% of the population Not all disabilities affect web usage
2 million people are blind or visually impaired The web improves access to services for some
disabled users BUT few sites are fully accessible NO right answer to design problems as some
accessibility requirements conflict Understanding the problems is the first step
to better design
Disability Types
Disability Types Visual Hearing Motor Learning Cognitive Photo-epilepsy Technological
Visual Disability (1): Blind Screen readers [JAWS (Kyle video), IBM HPR,
Window Eyes…] Output speech and/or Braille (for deaf/blind) Interprets text only Keyboard only Navigate using list of headings, links…
Design considerations Well-structured HTML Text descriptions for non-text elements Link text that is meaningful out of context Keyboard only access and shortcut links to skip
navigation plus Tab/Shift Tab through links using JAWS Design pages that ‘linearise’ and have chunks of
content
Visual Disability (2) Low vision
Screen magnifiers - e.g. Zoom Text
Design considerations Avoid images including text High contrast between text
and background, images… Place images close to
associated text Avoid need to scroll
horizontally
Visual Disability (3) Colour blindness
Design considerations Do not rely on colour alone to
convey information
Hearing Disability Use of multimedia (audio/video)
increasing Sign-language users
English is a second language Design considerations
Text transcripts for audio Synchronous captioning for video Clear simple concise English
Motor Disability Accident, arthritis, ME, RSI, elderly… Alternative input devices
Ergonomic keyboard, tracker ball Mouth stick or head wand with keyboard Single-switch access, sip and puff switch Microphone & voice recognition software
Design Considerations Avoid need for fine motor skills Keyboard only access Links to skip navigation and chunks of content Take account of fatigue
Learning Disability: Dyslexia
15-20% of population Visual processing problems
Object recognition Visual concentration Over-sensitivity to light
Recognising and sequencing letter sounds Reduced reading speed Difficulties with spelling and writing
Short term memory and sequencing Easily lost in web sites Forget backwards navigation
Dyslexia: Design Considerations
Navigation - simple and intuitive Content - broken into chunks Text formatting
Use sans-serif fonts Avoid underlining or CAPITALISATION Avoid changes in text spacing (fonts, double-justify) Avoid use of bold/italic (even for headings)
Support text with supplemental images Page background
Enable user setting for background colour (lilac?) Avoid background images
Customisation via style sheets http://www.dyslexia.com/qaweb.htm
Cognitive Disability Accident, stroke, autism, dementia,
Downs syndrome… Problem of effective communication Design considerations
Clear, simple and consistent navigation Clear and simple writing Supplemental media (images,
audio/video…)
Photo-epilepsy Design considerations
Blinking and moving content Alert users before automatic
display
Technological Disability Older browsers don't support current
W3C recommendations HTML (accessibility features) Cascading Style Sheets (CSS)
Monitors Size and resolution
(640x480, 800x600, 1024x768) Monochrome
Slow modem connection Users may turn off images, multimedia… Reluctance to download large files, plug-ins…
Web standards and the law
Why bother with accessibility? Because you should - ethical, inclusiveness Because you can Because it will benefit you …
by including more potential clients/customers/students
by enhancing the "user experience" for everyone Because it’s a legal requirement
Disability Discrimination Act, 1995 Special Educational Needs and Disability Act
(SENDA), 2002
Usable and Accessible - what does this mean? Web pages should be usable AND accessible Usability:
"is the quality of a system that makes it easy to learn, easy to use, easy to remember, error tolerant, and subjectively pleasing".
Jakob Nielsen, www.useit.com 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 and inventor of the Web Usability is about happier and more efficient
users Accessibility is about increasing number of users
W3C Recommendations W3C Worldwide web consortium
co-ordinates development of web technologies develops specifications, guidelines, standards,
software and tools W3C Web Content Accessibility Guidelines
(WCAG) WCAG for beginners Fourteen guidelines organised into three priority
levels Priority 1 (Level A) MUST be met Priority 2 (Level AA) SHOULD be met Priority 3 (Level AAA) MAY be met
Overview of SENDA Disability is ‘physical or mental impairment
effecting ability to carry out normal day-to-day activities’
Discrimination occurs if disabled students have a substantial disadvantage. [May be justifiable in some circumstances - maintaining academic standards, cost…]
Organisations should make reasonable adjustments
Adjustments should be anticipatory UK Policies http://www.w3.org/WAI/Policy/#UK/
Legislation Around the World Most countries in Europe adopting
variants of WCAG U.S.A.
Adopted Section 508 Subset of WCAG, similar to Priority 1
Omits some WCAG guidelines Contains some additional guidelines Some guidelines are more specific
www.jimthatcher.com/sidebyside.htm
ISO Special Working Group on Accessibility Extending ISO/DIS 9241 ‘Ergonomics
of human-system interaction – Guidance on software accessibility’
SWAG Home Page Target publication date March 2007
British Standards and Accessibility PAS 78 Download ONE copy of Guide
to good practice in commissioning accessible websites from Disability Rights Commission or purchase PAS 78 from BSI Standards
Strategies
StrategiesA. Provide alternative text only site
Limited web experience Targets vision-impaired users Secondary sites may be poorly maintained
B. Dynamic conversion to text only Betsie (BBC Education Text to Speech Internet Enhanc
er) Free Perl script Still limited web experience; targets vision-impaired
users Needs good HTML
C. Design-for-all (Universal Design in U.S.A.) Normally preferred approach
Corporate strategy Develop an accessibility strategy consider:
New materials / legacy materials Corporate site / intranet and e-learning materials Restrictions / staff training
Plan your site Research user needs Design your site, keep design FLEXIBLE
Use advisory service TechDis http://www.techdis.ac.uk/
Usability/Accessibility testing Implement standards XHTML/CSS and WCAG
Summary
Accessible design is a legal requirement A wide range of disabilities affect web
usage Each disability has specific requirements Design-for-all strategy is recommended
where feasible W3C provide guidelines Everyone benefits from accessible
design!