Web Content Accessibility Guidelines WCAG

1
Web Content Accessibility Guidelines (WCAG)

• Version 1.0 (Version 2.0 in development)
• 14 Guidelines
• Divided into 65 checkpoints
• 13 can be checked automatically by computer
  (e.g. images in a web site have ALT text)
• 52 need human judgment (e.g. do not rely on
  colour alone to convey information)

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Web Content Accessibility Guidelines (WCAG)

• Priority 1 A Web content developer must satisfy
  this checkpoint. Otherwise one or more groups
  will find it impossible to access information
  Satisfying this checkpoint is a basic requirement
  for some groups to be able to use Web documents.
• Priority 2 A Web content developer should
  satisfy this checkpoint. Otherwise one of more
  groups will find it difficult to access
  information Satisfying this checkpoint will
  remove significant barriers to accessing Web
  documents.
• Priority 3 A Web content developer may address
  this checkpoint. Otherwise, one or more groups
  will find it somewhat difficult to access
  information . Satisfying this checkpoint will
  improve access to Web documents.

3
Checkpoints accounting for most problems

• 1.1 Provide a text equivalent for every non-text
  element
• 2.2 Ensure that foreground and background colour
  combinations provide sufficient contrast
• 6.3 Ensure that pages are usable when scripts,
  applets and other programmatic objects are turned
  off
• 7.3 Until user agents allow users to freeze
  moving content, avoid movement in pages

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• 10.1 Until user agents (browsers, assistive
  technologies) allow users to turn off spawned
  windows, do not cause pop-ups or other windows to
  appear
• 12.3 Divide large blocks of information into
  more manageable groups where natural and
  appropriate
• 13.1 Clearly identify the target of each link
• 14.1 Use the clearest and simplest language
  appropriate for a sites content

5
Problems experienced by blind users

• Incompatibility between screen reading software
  and web pages (26)
• Incorrect or non-existent labelling of links,
  form elements and frames (24)
• Cluttered and complex page structures (23)
• ALT tags on images non-existent or unhelpful (16)
• Confusing and disorienting navigation mechanisms
  (16)

6
Problems experienced by partially sighted users

• Inappropriate use of colours and poor contrast
  between content and background (20)
• Incompatibility between assistive technology
  (e.g. for magnification) and web pages (19)
• Unclear and confusing layout of pages (18)
• Confusing and disorienting layout of pages (18)
• Confusing and disorienting navigation mechanisms
  (16)
• Graphics and text size too small (10)

7
Problems experienced by physically impaired users

• Confusing and disorienting navigation mechanisms
  (20)
• Unclear and confusing layout of pages (19)
• Graphics and text size too small (11)
• Inappropriate use of colours and poor contrast
  between content and background (10)

8
Problems experienced by Deaf/hearing impaired
users

• Unclear and confusing layout of pages (23)
• Confusing and disorienting navigation mechanisms
  (12)
• Lack of alternative media for audio-based
  information and complex terms/language (10)
• Inappropriate use of colours and poor contrast
  between content and background (9)
• Graphics and text size too small (9)

9
Problems experienced by dyslexic users

• Unclear and confusing layout of pages (41)
• Confusing and disorienting navigation mechanisms
  (32)
• Inappropriate use of colours and poor contrast
  between content and background (20)
• Graphics and text size too small (14)
• Complicated language or terminology (7)