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Discussion: Text Alternative Survey

From: Laura Carlson <laura.lee.carlson@gmail.com>
Date: Fri, 23 Apr 2010 01:18:42 -0500
Message-ID: <w2u1c8dbcaa1004222318o9f11d6bdo6afc4b9011fe8432@mail.gmail.com>
To: Dave Singer <singer@apple.com>, Ian Hickson <ian@hixie.ch>, Matt Morgan-May <mattmay@adobe.com>, HTML Accessibility Task Force <public-html-a11y@w3.org>
Hi all,

Thanks to everyone who completed the "Call for Consensus: Text
Alternatives" survey [1].

I am  especially grateful to Dave and Ian for your comments. They are
points that need discussion and consideration. Thank you.

Dave commented on the survey:

> A) The replacement text falls far short of the editorial quality of the text it replaces.

Any suggestions for improvement? I'd really appreciate help from you
or anyone else. I'm no spec writer as you probably can tell <smile>.

> B) Serious issue: Whether or not we say that authoring tools must
> generate conforming documents, anyone writing a tool would normally
> wish to and expect to, and may well be instructed to by their
> management. Being silent on the subject, as the replacement text is,
>  will simply encourage the behavior of putting in 'nonce' values (e.g.
>  alt="" or alt="<file-name>").

WAI CG said that they would not object to allowing a "generated" or
"missing" attribute to address this point. [2]  The document says, "In
order to address both the validity and human generation concerns, we
do not oppose the creation of 'autogenerated' and 'missing' attributes
where either one of these could be used to make an image that does not
have any human-generated text alternatives valid. (Note: It is
important that this marker is not included in the alternative text
string itself.)"

I submitted bugs for both generated and missing attributes. Ian
rejected the generated attribute [3] bug as WONTFIX.

The missing attribute bug is marked NEEDSINFO [4]. The missing
attribute was Matt May's original idea from the 2009 WAI CG Task Force
meetings. I tried to document his idea as best I could on the "Short
Text Alternatives on <img>" Wiki page [5]. Creating  a missing
attribute would allow "images whose contents are not known" to be
labeled as such. It would enable tools to quickly discern where text
alternatives are needed and allow for future improvement. It would be
great if would work as it could crowdsource occurrences of missing
alt. I wrote to Matt on April 2 and asked him to explain the technical
details on the bug. He hasn't yet. Hopefully he will. I am thinking
that perhaps a better name for that attribute might be "incomplete".

Both "generated" and "missing" attributes were in earlier versions of
the change proposal. I took them out at the request of the people who
attended the face-to-face meeting. I'm not sure why they wanted them
out. Missing could go into separate Change Proposal or returned to
this one if people think it is a good idea and we can iron out the
technical details.

> c) [Minor] one of the lines (the one about paragraphs) is already gone from the editor's
>  draft at <http://dev.w3.org/html5/spec/Overview.html#guidance-for-conformance-
> checkers

Yes, I'm aware of that [6]. I'm leaving it in place for now, as it
could reappear.

Ian commented on the survey:

> It violates layering by making it possible for removal of ARIA to
> affect conformance,

Ian, could you explain this further? I did not attend the WAI CG
sessions when the ARIA options were added. We should have solid
rationale for the options listed. If layering is a problem, let's try
to figure it out here.

Right now the only item listed in the set that I am positive of is the
mandatory alt attribute.

>  discourages use of semantic HTML by removing the
>  allowance for using title="" for titles,

Using title="" is problematic as it cannot be relied upon as alt can.
It is only safe to use for extra, advisory information.

>  and encourages longer markup than necessary by suggesting the use of
> role="presentation" to imply alt="" when alt="", which is shorter,
> already implies role="presentation".

This is a good point, Ian. Shorter is usually better. The current
rationale states:
"role="presentation" programmatically conveys to assistive technology
that an image is presentational and not of interest."

Does anyone have further/better rationale for why role="presentation" is needed?

Thanks again for your comments. If you have these concerns, I'm sure
others will too.

Best Regards,
Laura

[1] http://www.w3.org/2002/09/wbs/44061/20040422_text-alt/results
[2] http://www.w3.org/2009/06/Text-Alternatives-in-HTML5
[3] http://www.w3.org/Bugs/Public/show_bug.cgi?id=9212
[4] http://www.w3.org/Bugs/Public/show_bug.cgi?id=9213
[5] http://www.w3.org/html/wg/wiki/IssueAltAttribute#Missing_Attribute
[6] http://www.w3.org/Bugs/Public/show_bug.cgi?id=9217

-- 
Laura L. Carlson
Received on Friday, 23 April 2010 06:19:15 GMT

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