Web content accessibility guidelines

Web Content Accessibility Guidelines (WCAG)

  • The Web Content Accessibility Guidelines, often known as WCAG, is an internationally recognised benchmark for measuring the accessibility of websites.
  • The current version of the Web Content Accessibility Guidelines is WCAG 2.0.
  • What are the differences between WCAG 1.0 and WCAG 2.0?
  • Terminology: WCAG 2.0 introduces design principles and refers to success criteria instead of checkpoints.
  • Technology independence: the WCAG 2.0 guidelines and success criteria are written so they can be applied to any web technology, not just HTML.
  • Testable: WCAG 2.0 success criteria include specific statements outlining the minimum requirements to achieve accessibility and details of techniques describing how to do this.
  • Most websites that conform to WCAG 1.0 will not require significant changes in order to conform to WCAG 2.0.

Structure of WCAG 2.0

  • The WCAG guidelines are grouped under four design principles: perceivable, operable, understandable and robust.
  • Within each guideline is a series of success criteria that describes what a web developer or designer needs to do to create an accessible website.
  • Against each success criterion there are a number of techniques that explain how to meet the requirement using different web technologies.

WCAG 2.0

  • 4 design principles
    • 12 guidelines
      • Level A: 25 Success criteria
        • Techniques
      • Level B: 13 Success criteria
        • Techniques
      • Level AAA: 23 Success criteria
        • Techniques

Can I use JavaScript, PDF, Flash and other web technologies?

  • Web technologies that have specific techniques to meet WCAG 2.0, and are understood by assistive technologies (e.g. screen readers), are described as accessibility-supported.
  • Currently there is no definitive list of accessibility-supported technologies. HTML is widely regarded as accessible, as is CSS and JavaScript in most circumstances.
  • Vision Australia recommends seeking advice from accessibility experts, and the Australian Human Rights Commission, before implementing other technologies.

Conformance levels

  • The WCAG 2.0 success criteria are grouped into three levels (A, AA and AAA) that describe their priority of importance for accessibility, with Level AAA providing maximum accessibility.
  • Level A describes items that will prevent users from accessing web pages (eg. keyboard access is required so that a person who cannot use the mouse can use the website).
  • Level AA describes items that users could work around, providing they have the right technology or skill (e.g. if the text size is too small some users will increase this using their browser or assistive technology, but it is an extra adjustment they need to make).
  • Level AAA describes items that will improve the understanding of content and help specific audiences (e.g. sign language representations of video content are the most effective way to communicate with many people who are deaf).

Web Accessibility in Australia

  • Organisations that fail to make their web information and services accessible are liable for complaints and legal action under:
  • Australian Disability Discrimination Act (1992)
  • United Nations Convention on Rights of Persons with a Disability (2006)
  • The Australian Human Rights Commission provides an advisory note explaining what organisations can do to meet their obligations

Australian Government National Transition Strategy

  • In June 2010 the Australian Government released its Web Accessibility National Transition Strategy (NTS) to adopt WCAG 2.0.
  • All federal, state and territory government websites need to meet WCAG 2.0 Level A conformance by 31 December 2012.
  • All federal government websites have an extended requirement to meet WCAG 2.0 Level AA conformance by 31 December 2014.

Useful references

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