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Use of WCAG 2.0 Techniques and Failures

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This is a DRAFT resource being prepared by the WCAG Working Group. It will need review by other WAI groups as well. Exactly how it will be published is still to be determined.


February 14, 2013 (Rev Apr 18)

Summary

  • ‘WCAG 2.0 Sufficient Techniques’ are not the only sufficient techniques and should never be required as the only way to meet WCAG 2.0 success criteria.
  • ‘WCAG 2.0 Advisory Techniques’ should always be considered but are not sufficient.
  • ‘WCAG 2.0 Failures’ are designed to always indicate a failure.


WCAG 2.0 Sufficient Techniques


First, it is important to distinguish between ‘ A) sufficient techniques’ and the B) WCAG Working Group’s ‘Sufficient Techniques’.

A) sufficient techniques:

  • are any technique that meets the success criterion
  • these may be developed by anyone


B) the "WCAG Working Group’s Sufficient Techniques"

  • are techniques that have been documented by the WCAG 2.0 Working Group as an aid to developers,
    • they provide EXAMPLES of solutions that would be sufficient to meet each success criterion.
    • but they are NOT the ONLY way of meeting WCAG success criteria
    • and, WCAG 2.0 Sufficient Techniques should never be required as the only way to meet a WCAG Success Criterion.
      • It may be appropriate to require that techniques other than W2 Sufficient Techniques be justified, but they should always be allowed. As noted above, other techniques may not only be sufficient, but may be better for a particular situation as well.
    • The only thing that should be required, is the Success Criteria themselves.



RATIONALE

  1. It is not always possible to use one of the WCAG WG documented Sufficient Techniques.
    • restricting authors to only being able to use WCAG WG documented Sufficient Techniques means they will sometime have no techniques they can use
  2. We do not have W2 Sufficient Techniques documented for all web technologies being used today.
  3. We have not captured all of the techniques that would be sufficient, even for the established technologies – and developers should not be restricted to using only those the Working Group has had time to write-up.
    • restricting authors to only being able to use WCAG WG documented Sufficient Techniques means they will not be able to use all technologies today - including technologies that can be accessible
  4. The W2 Sufficient Techniques are not always the best techniques, and on some pages, may not be good to use.
    • Other techniques may not only be sufficient, but may aso be much more effective on particular web pages
  5. WCAG Sufficient Techniques are only sufficient to meet a Success Criterion if the technique is accessibility supported in the environment they are being used.
  6. MOST IMPORTANTLY:
    • If "WCAG 2.0 sufficient techniques" are required by requirement (or regulation or rule) as the only techniques that will be accepted as sufficient,
      • then it will be a violation of those requirements, (or regulations or rules) to use any new technologies from any company or standards group for a year or more after their introduction to the public.
        • (Because this is the time it is likely to take for the WCAG working group to become familiar with the technologies, then develop, put out for public comment, test with assistive technologies and user agents, revise and publish sufficient techniques for the technologies.)



WCAG 2.0 Advisory Techniques

The WCAG 2.0 Advisory Techniques are additional techniques that have been documented by the WCAG 2.0 Working group. They are advisory, rather than sufficient, techniques for any of a number of reasons including:

  • they are not yet accessibility supported (assistive technologies don't work with them yet)
  • they are not always applicable or practical;
  • they are not always effective and sometimes may make things worse for some group;
  • the technology they are based on is not yet stable
  • they do not address the success criterion itself, but provide related accessibility benefits.

However these techniques are often very helpful to one or more groups, and they may be the only way that some groups can access some types of information or sites. So they should always be considered, and should be used where appropriate and possible.

WCAG 2.0 Failures

The WCAG 2.0 Failures are designed to always identify a failure to meet a success criterion. As a result, a failure should be able to be relied upon to indicate failure to meet the success criterion (unless an equivalent version that does not meet the failure is provided). (See Conformance requirements 1 and 5.)

NOTE: If anyone identifies a situation where a Failure is TRUE but the page DOES meet the success criterion (i.e. the failure is TRUE but there is no true failure to meet the SC), please report it immediately to the WCAG 2.0 Working Group so that the failure language can be fixed or the failure removed.

See also http://www.w3.org/TR/WCAG20-TECHS/intro.html#suff-adv-techs






EDITS THAT HAVE BEEN SUGGESTED

  1. Change first bullet at top, and the lead sentence on the last paragraph under Sufficient Techniques from should not be required to are not recommended to be required
    • ARGUMENTS FOR THIS:
      • We shouldn’t be so definite or assertive
      • Some places have already required them and this would create complications
      • If WCAG Sufficient techniques are not required then it is unclear exactly what is sufficient
    • ARGUMENTS AGAINST:
      • Even WCAG Sufficient Techniques are not sufficient if they are not accessibility supported in the environments in which they are used.
      • See reasons numbered 1 to 6 above why they should not ever be required
      • Especially note #6 which points out that such a policy would prevent the use of new technologies (and even old technologies that WCAG WG hasn’t documented techniques for)
      • Requiring the WCAG WG Sufficient Techniques would violate the principles that were stated when WCAG was reviewed and when consensus was established to pass the Standard. The standard would never have been passed/established with those restrictions.


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