ChangeProposals/Issue122DeferToWCAG

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Change Proposal ISSUE-122: Defer Thematic and Presentational Examples to WCAG

  • HTML5 ISSUE-122 shalott-example
  • Editor: Laura Carlson
  • Date: February 13, 2011.
  • Please address feedback to the HTML Working Group mailing list (public-html@w3.org)

Summary

Remove thematic and presentational text alternative examples from HTML drafts. Give the examples to the Web Content Accessibility Guidelines Working Group (WCAG WG) to incorporate into their specs and technique documents. Let the accessibility requirements on the possible values of the text alternatives be defined by WCAG 2.0 and not HTML5. Add a prominent reference to WCAG 2.0 and its techniques for authors to obtain this information.

Rationale

At times the value for text alternatives is subjective. This is especially true for mood-setting images such as Issue 122's Bug 9077 and Bug 9081. It is difficult to come up with a general "best rule" for images that "enhance the themes or subject matter of the page content" since in many cases like this, it is a matter of style. If we made a test and asked 10 different accessibility professionals to provide text alternatives, we will likely get 10 different answers. Throw in 400 HTML working group members and we can up that number to 410 different answers. In fact, we can get different answers from different blind folks as well (i.e. people blind from birth versus people who become blind later in life). If we are looking for consistency in these text alternative values, we will fail, since we won't be able to please all of the people all of the time.

The best HTML5 can do is to point authors to the W3C's domain that is chartered to deal with these issues. That domain is the Web Accessibility Initiative (WAI). WAI's WCAG, WG Authoring Tool Accessibility Guidelines Working Group (AUWG), User Agent Working Group (UAWG) etc are chartered to set accessibility guidelines and HTML WG is not. Providing the mechanism(s) for a text alternative is an inalienable HTML WG concern. Whereas providing guidance on values for alternative text is an inalienable WAI concern.

Positive Effects

  • Refers authors to the WAI's Web Content Accessibility Guidelines 2.0 (WCAG). Accessibility is WAI's domain and specialty. If any group has a chance to find an answer, WAI is that group. WAI develops guidelines which are widely regarded as the international standard for Web accessibility. WAI's WCAG defines how to make Web content more accessible to people with disabilities.
  • Eliminates repetition and conflicting information within the HTML Working Group.
  • Is consistent with both HTML5 and HTML 4 precedent for deferring accessibility concerns to the WAI domain.
    • The HTML5 ISSUE-66 decision said that UAAG is the proper place to provide Image Analysis Heuristics assistance. Image Analysis Heuristics language was removed from HTML5 and given to UAAG.
    • HTML4 states, "Implementors should consult the section on accessibility for information about how to handle cases of omitted alternate text." The notes on accessibility section, refers people to the Web Content Accessibility Guidelines, the User Agent Accessibility Guidelines, and the Authoring Tool Accessibility Guidelines.
  • Alleviates duplication of effort and double maintenance.
  • Eliminates repetition and conflicting information between the HTML WG and WAI Working Groups.
  • If ever needed, WAI has built in cross group accessibility coordination. The WAI coordination group exists to harmonize common accessibility cross group topics. For instance besides WCAG, another group under the WAI CG umbrella, is the UA WG. WCAG provides content language. UAWG provides UA language. For example 3.1.1 of the User Agent Accessibility Guidelines deals with UAs identifying the presence of alternative content.
  • Is in accord with WAI CG's Consensus Resolutions on Text alternatives in HTML 5 as they recommended:
    • that HTML5 state that "For guidance on accessibility requirements for text alternatives authors should consult WCAG 2.0."
    • and that HTML should not provide any guidance that conflicts with WCAG.
  • Benefits other use cases besides the disabled (i.e. people who turn off images, users who have expensive data roaming connections, users with text-only browsers, users with voice browsers in vehicles). WAI has addressed these types of auxiliary benefits and business use cases for years.
  • As one study indicates, users prefer embedded reference links into the body of a document instead of lumping them all into one section. They believed that embedding the links within a document made it easier to navigate, easier to recognize key information, easier to follow the main idea of the passages, and promoted comprehension.

Negative Effects

Details

Remove:

Suggested text to add:

For guidance on accessibility requirements for possible text alternative values for thematic and presentational images please consult WCAG 2.0 and Techniques for WCAG 2.0.

Special Thanks To:

References