Ian's comments on XAG

These are comments on an old draft (29 Aug - TR draft) that has been
superseded, but the comments may still apply in some instances to the
current draft. These comments are forwarded with permission:

  - I don't think that XAG should (all but) equate accessibility
    and device independence. Issues like simplicity, orientation,
    and navigation mechanisms are not always related to device
    independence, yet are part of WCAG 1.0.

  - I think checkpoints 1.2 and 2.1 are so general as to be
    not that useful. Please be more specific; pick the most
    important cases and make a few extra checkpoints.

  - I don't know why checkpoint 1.3 (on reuse) is limited to
    modules for alternative-equivalent relationships. Why
    not "reuse modules from other specs that satisfy the
    requirements of XAG [except for this one to avoid looping]"?
    So, that means if a piece of format F satisfies 1.1, then
    1.3 says "In format G, reuse that good piece of F".

  - I think the example in techniques for 1.2 could be better.
    There's no need to talk about namespaces in the mydoc:para
    part; people either will understand namespaces or not.
    Make the example less geeky.

  - In checkpoint 1.3:  "There's a non-negligeable cost for
    your authors to learn new concepts." While that may be
    true, there's also a cost to using elements from 10 different
    namespaces; I had an interesting discussion with Tantek Celik
    about this [and he thinks that mixing and matching may
    complicate authoring to the point of making things unusable.]
    In short, reuse is generally a good thing, but for instance,
    would you rather a format designer implement the html:p element
    and that's it (out of 100 elements), or just include the
    p element in the local DTD?

    Also, the quote above suggests strongly that there's an
    expectation authors will be aware of markup (and thus
    won't have to learn concepts since they are already
    familiar with the old markup). Should we be assuming this
    much that authors will be looking at markup?

  - The first sentence in techniques for 1.2 is hard to understand.

  - In checkpoint 1.2: "it is probably that many more people would be
    associating images with text/markup runs." Do we have evidence
    for that (e.g., in another format where it's possible to make
    the association)? Maybe just change "probable" to something
    like "it would be a lot easier to do if people want to".

  - In checkpoint 2.1: "Ensure all semantics are capture in markup in
    a repurposable form."

     - Does this mean that scripts are illegal in XAG formats?
     - Rather than talk about what's repurposable (since a lot is),
       maybe it's easy to talk about what is not, and to suggest
       avoiding that. For instance "Don't encode semantics in
       bitmaps; use markup."

  - In checkpoint 2.2: "Separate presentation properties using
    stylesheet technology/styling mechanisms."

    Does this mean that HTML/SVG can't conform to XAG? Perhaps
    the requirement should be something like:

     1. Separate presentation properties using
       stylesheet technology/styling mechanisms.

     2. Any conforming user agent for the format must
       implement the style mechanisms.

     3. A format may *also* include style elements and
        attributes in markup, but it's not recommended.

     4. If a format includes style elements and attributes,
        the format must define their interaction with the
        style mechanisms (e.g., how they cascade).



-- 
Charles McCathieNevile    http://www.w3.org/People/Charles  phone: +61 409 134 136
W3C Web Accessibility Initiative     http://www.w3.org/WAI  fax: +33 4 92 38 78 22
Location: 21 Mitchell street FOOTSCRAY Vic 3011, Australia
(or W3C INRIA, Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France)

Received on Tuesday, 9 April 2002 15:20:12 UTC