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[Proposal] Conformance profiles for UAAG 1.0

From: Ian B. Jacobs <ij@w3.org>
Date: Fri, 10 May 2002 12:06:34 -0400
Message-ID: <3CDBF00A.7030905@w3.org>
To: w3c-wai-ua@w3.org
CC: robla@real.com
Dear UAWG,

I received an action item at the 4 April 2002 teleconference [1]
to propose some text for the chapter on conformance about
"conformance profiles" for other specifications (issue 520 [2]).

  - Ian

[1]
http://lists.w3.org/Archives/Public/w3c-wai-ua/2002AprJun/0027
[2] http://www.w3.org/WAI/UA/issues/issues-linear-cr2#520


<PROPOSAL>
3.11 Including UAAG 1.0 requirements in other specifications

Authors of technical specifications (such as W3C Recommendations)
should incorporate the requirements of UAAG 1.0 as part of
conformance to their specifications. This may be done by direct
inclusion, or by reference using a conformance profile.  Direct
inclusion promotes the integration of accessibility requirements;
inclusion by reference is easier to do.

3.11.1 General tips

  1) Identify accessibility features of the specification where
  they are defined (see checkpoint 8.1). Optionally, create an
  appendix of these accessibility features as well.

  2) Remember to include user interface requirements as part of
  conformance to the specification.  Authors of technical
  specifications tend to focus more on rendering or other
  content-related behavior and less on user interface
  requirements. UAAG 1.0 makes a number of user interface
  requirements that authors will need to consider (such as those
  in Guideline 5 pertaining to viewport behavior).

  3) Include a general reference to UAAG 1.0 and Techniques for
  UAAG 1.0 (see the section "How to refer to UAAG 1.0").

For more information on designing specifications that promote
accessibility, refer to WAI's "XML Accessibility Guidelines"
[XAG10].

3.11.2 Direct inclusion of requirements

  1) Rather than include the generic UAAG 1.0 requirements, tailor
  them to the specification. Be specific in the requirement, and
  include (in context) a reference to the original UAAG 1.0
  checkpoint.  The following examples illustrate what is
  meant by direct inclusion:

   - In an HTML specification, where the SCRIPT, APPLET, and
   OBJECT elements are defined, include a statement such as "Per
   checkpoint 3.4 of UAAG 1.0, a conforming user agent must allow
   configuration not to execute scripts, applets, or other
   executable content."

   - In a CSS specification, where the 'text-decoration' property
   is defined, include a statement such as "A conforming user
   agent must either:
       a) allow configuration to override the 'blink' value
          with the 'none' value, or
       b) ignore the 'blink' value.
   This is required by checkpoint 3.3 of UAAG 1.0 [UAAG10]."

  Note how these examples refer to the specific elements,
  attributes, properties, etc. of the specifications.

  2) Including some UAAG 1.0 requirements in a specification is
  better than including no requirements. However, since UAAG 1.0
  requirements are designed to complement one another, arbitrary
  selection of requirements may result in accessibility gaps.
  Authors are encouraged to select requirements in groups defined
  by the conditional content mechanisms of content, selection,
  and input modality labels.

3.11.3 Conformance profiles

Section G.5 of the SVG 1.0 Recommendation states:

  "Additionally, an authoring tool which is a Conforming SVG
  Generator conforms to all of the Priority 1 accessibility
  guidelines from the document "Authoring Tool Accessibility
  Guidelines 1.0" [ATAG] that are relevant to generators of SVG
  content."

This statement requires conformance to the Authoring Tool
Accessibility Guidelines as part of conformance to SVG 1.0 (for
certain classes of tools). This type of "conformance requirement
by reference" is also possible for UAAG 1.0. However, since
conditional conformance (section 3.2) to UAAG 1.0 can vary beyond
three conformance levels, it is important for references to state
precisely what is required. This is called a conformance profile.

This section explains how to create a valid conformance profile
to UAAG 1.0. UAAG 1.0 does not define any (named) conformance
profiles, just the mechanism for creating them.

A valid conformance profile must include the following
information:

  1) The guidelines title/version

  2) The conformance level required: "A", "Double-A", or
     "Triple-A".

  3) Content type labels: The profile must include at
     least one content type label (whose requirements
     must be satisfied).

  4) Selection label: The profile must indicate whether
     a conforming user agent is required to implement
     a selection mechanism.

A valid conformance profile should include the following
information:

  1) Applicability: Which checkpoints (or portions of checkpoints)
  do not apply for this specification. For instance, if a
  specification does not define "tables", the conformance profile
  should indicate that checkpoint 10.1 does not
  apply. Specification authors should include rationale in their
  profiles that explains why a checkpoint does not apply.

A valid conformance profile may include the following
information:

  1) Input modality labels: If conformance for pointer or voice
  input is required in addition to keyboard input.

Note that the following are always required and therefore need
not appear in a conformance profile:

  1) Keyboard input requirements
  2) Content focus requirements (only when the content includes
     enabled elements; see checkpoint 9.1).

The following is an example of a valid conformance profile:

<EXAMPLE>
  "As part of conformance to MyFormat 1.0, a user agent must
   satisfy the following conformance profile of the
   "User Agent Accessibility Guidelines 1.0" [UAAG10]:

   a) Conformance Level A

   b) Content type labels: VisualText, ColorText, Image,
      Animation, and Video. This means that a conforming
      MyFormat user agent must satisfy the requirements
      associated with those labels; refer to UAAG 1.0
      section 3.5 for details.

   c) Selection: A conforming MyFormat user agent must
      implement a text selection mechanism, and therefore
      satisfy the requirements associated with the UAAG 1.0
      selection label; refer to UAAG 1.0 section 3.7
      for details. A conforming MyFormat user agent is
      only required to allow users to select text content.

   d) Applicability: The following UAAG 1.0 checkpoints
      do not apply to MyFormat and therefore do not need
      to be satisfied for conformance to this specification:

       - 1.2, 3.4, 9.5, 9.6: MyFormat does not allow inclusion
                             of scripts. Thus, there are
                             no author-supplied event handlers.
       - 2.4, 2.6: MyFormat does not involve synchronization.
       - 2.5, 4.6: MyFormat does not define captions.
       - 10.1: MyFormat does not define tables.
       [And so on]
</EXAMPLE>

Then, in the references section, include the URI of the UAAG
1.0 specification.

</PROPOSAL>

Notes on the proposal:

  - I don't think it's necessary to say anything special about
  mixing formats (e.g., XHTML + MathML + SVG), but I haven't
  thought about it much.

-- 
Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
Tel:                     +1 718 260-9447
Received on Friday, 10 May 2002 12:40:05 GMT

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