Transcript Web accessibility for all

Birkbeck University of London
Business 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
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Disability and the web
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Disability types
Design considerations
Web standards and the law
Strategies
Disability and the web
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8.5 million adults registered disabled in the UK
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2 million people are blind or visually impaired
The web improves access to services for some
disabled users BUT
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14% of the population
Not all disabilities affect web usage
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
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Visual
Hearing
Motor
Learning
Cognitive
Photo-epilepsy
Technological
Visual Disability (1): Blind
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Screen readers [JAWS (Kyle video), IBM HPR,
Window Eyes…]
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Output speech and/or Braille (for deaf/blind)
Interprets text only
Keyboard only
Navigate using list of headings, links…
Design considerations
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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)
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Low vision
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Screen magnifiers - e.g. Zoom
Text
Design considerations
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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)
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Colour blindness
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Design considerations
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Do not rely on colour alone to
convey information
Hearing Disability
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Use of multimedia (audio/video) increasing
Sign-language users
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English is a second language
Design considerations
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Text transcripts for audio
Synchronous captioning for video
Clear simple concise English
Motor Disability
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Accident, arthritis, ME, RSI, elderly…
Alternative input devices
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Ergonomic keyboard, tracker ball
Mouth stick or head wand with keyboard
Single-switch access, sip and puff switch
Microphone & voice recognition software
Design Considerations
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Avoid need for fine motor skills
Keyboard only access
Links to skip navigation and chunks of content
Take account of fatigue
Learning Disability: Dyslexia
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15-20% of population
Visual processing problems
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Recognising and sequencing letter sounds
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Object recognition
Visual concentration
Over-sensitivity to light
Reduced reading speed
Difficulties with spelling and writing
Short term memory and sequencing
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Easily lost in web sites
Forget backwards navigation
Dyslexia: Design Considerations
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Navigation - simple and intuitive
Content - broken into chunks
Text formatting
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Support text with supplemental images
Page background
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Use sans-serif fonts
Avoid underlining or CAPITALISATION
Avoid changes in text spacing (fonts, double-justify)
Avoid use of bold/italic (even for headings)
Enable user setting for background colour (lilac?)
Avoid background images
Customisation via style sheets
http://www.dyslexia.com/qaweb.htm
Cognitive Disability
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Accident, stroke, autism, dementia, Downs
syndrome…
Problem of effective communication
Design considerations
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Clear, simple and consistent navigation
Clear and simple writing
Supplemental media (images, audio/video…)
Photo-epilepsy
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Design considerations
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Blinking and moving content
Alert users before automatic
display
Technological Disability
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Older browsers don't support current
W3C recommendations
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Monitors
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HTML (accessibility features)
Cascading Style Sheets (CSS)
Size and resolution
(640x480, 800x600, 1024x768)
Monochrome
Slow modem connection
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Users may turn off images, multimedia…
Reluctance to download large files, plug-ins…
Web standards and the law
Why bother with accessibility?
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Because you should - ethical, inclusiveness
Because you can
Because it will benefit you …
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by including more potential clients/customers/students
by enhancing the "user experience" for everyone
Because it’s a legal requirement
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Disability Discrimination Act, 1995
Special Educational Needs and Disability Act (SENDA), 2002
Usable and Accessible - what
does this mean?
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Web pages should be usable AND accessible
Usability:
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"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
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Accessibility:
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"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
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Usability is about happier and more efficient users
Accessibility is about increasing number of users
W3C Recommendations
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W3C Worldwide web consortium
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co-ordinates development of web technologies
develops specifications, guidelines, standards, software and
tools
W3C Web Content Accessibility Guidelines (WCAG)
WCAG for beginners
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Fourteen guidelines organised into three priority levels
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Priority 1 (Level A) MUST be met
Priority 2 (Level AA) SHOULD be met
Priority 3 (Level AAA) MAY be met
Overview of SENDA
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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
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Most countries in Europe adopting variants of
WCAG
U.S.A.
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Adopted Section 508
Subset of WCAG, similar to Priority 1
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Omits some WCAG guidelines
Contains some additional guidelines
Some guidelines are more specific
www.jimthatcher.com/sidebyside.htm
ISO Special Working Group on
Accessibility
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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
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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
Strategies
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Provide alternative text only site
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B.
Dynamic conversion to text only
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C.
Limited web experience
Targets vision-impaired users
Secondary sites may be poorly maintained
Betsie (BBC Education Text to Speech Internet Enhancer)
Free Perl script
Still limited web experience; targets vision-impaired users
Needs good HTML
Design-for-all (Universal Design in U.S.A.)
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Normally preferred approach
Corporate strategy
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Develop an accessibility strategy consider:
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Plan your site
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Research user needs
Design your site, keep design FLEXIBLE
Use advisory service
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New materials / legacy materials
Corporate site / intranet and e-learning materials
Restrictions / staff training
TechDis http://www.techdis.ac.uk/
Usability/Accessibility testing
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Implement standards XHTML/CSS and WCAG
Summary
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Accessible design is a legal requirement
A wide range of disabilities affect web usage
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Each disability has specific requirements
Design-for-all strategy is recommended where
feasible
W3C provide guidelines
Everyone benefits from accessible design!