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Checkpoints 2.52, 2.58, 2.59 (ALT text)

From: Charles McCathieNevile <charles@w3.org>
Date: Mon, 8 Feb 1999 12:53:01 -0500 (EST)
To: WAI AU Guidelines <w3c-wai-au@w3.org>
Message-ID: <Pine.LNX.4.04.9902081231090.7435-100000@tux.w3.org>
Checkpoints 2.5.2 and 2.5.9 are nearly identical. Both deal with inserting
pre-written alternative content for grahics, and I think they should be
combined.

Checkpoint 2.5.8 appears to flatly condtradict them by stating that
default or generated ALT text should not be used.


Checkpoints:
Prompt the user for alternative content (ALT text, LONGDESC, etc). Do not
generate 'placeholder' content. Allow the user the option of specifying a
null value.

Techniques:
Where a purpose-written default exists (e.g. "search" as ALT for an icon,
or a pre-written description of an image) it may be offered as a default.
A user should be provided with the option of specifying a null value.

This approach slightly shifts the emphasis of section 2.5 from providing
tools which handle the work to providing mechanisms such as prompting and
alerting the user. However it does not preclude using such tools, and they
should be strongly promoted in the Techniques (analagous to the use of
CSS2 for a user agent, which _may_ not be necessary to provide
accessibility, but may be far and away the best strategy for achieveing
certain necessary goals.)

I think we should also consider the following approach

Guideline:
Where a user refuses to provide necesary information, attempt repair
strategies.

Checkpoint:

If and only if a user has failed to provide alternative text, the tool may
elect to use a filename or other emergency repair strategy. NOTE: The use
of such a strategy should be regarded as an accessiblity problem, and
checked for - see guideline 2.4 Identify and allow the user to correct
accessibility problems

Charles

--Charles McCathieNevile            mailto:charles@w3.org
phone: +1 617 258 0992   http://purl.oclc.org/net/charles
W3C Web Accessibility Initiative    http://www.w3.org/WAI
MIT/LCS  -  545 Technology sq., Cambridge MA, 02139,  USA
Received on Monday, 8 February 1999 12:53:04 GMT

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