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Re: User supplying image but not text alternative

From: Jan Richards <jan.richards@utoronto.ca>
Date: Wed, 20 Aug 2008 09:47:21 -0400
Message-ID: <48AC2069.7030500@utoronto.ca>
To: Henri Sivonen <hsivonen@iki.fi>
CC: WAI-AUWG List <w3c-wai-au@w3.org>

Hi Henri,

Thanks for the comment.

There's a couple of relevant guidelines...

The first is "Guideline B.1.3 Ensure that automatically generated 
content is accessible." 

Its success criteria require "automatically generate[d] content [to 
meet] the level 'A' Web content accessibility benchmarks at the 
conclusion of the automatic generation process (e.g., when inserted into 
the existing content)"

Its notes ("Related", "Accessibility Note 1", "Accessibility Note 2") 
are clear that if accessibility information is required from authors 
during the automatic generation process, see the author will need to be 
prompted. But that tools are not responsible if the author then ignores 
prompts for accessibility information or provides faulty information.

Guideline B.2.4 ("Assist authors to manage, edit, and reuse equivalent 
alternatives for non-text objects") is also relevant. It has a Level AA 
requirement re: which sources are acceptable for text alternatives and 
it also has a note that "Equivalent alternatives should not be 
automatically generated from unreliable sources (e.g., file names should 
not be used as text alternatives)."

So for a media media sharing site, I interpret this to mean:
- since information is required from the author to make a generated page 
of photographs accessible, the author should be prompted (NOT forced ) 
to add it. ATAG 2.0 never advocates forcing because it just leads to 
- assuming the author ignores the prompt the tool is not required to 
enter anything for the author - but they must continue to allow the 
author to add the required information if they so desire in the future 
(and an unobtrusive flag would help meet ATAG's checking requirement).
- sorry, but whether or not the resulting content (i.e., with a missing 
alt attribute) would be valid is up to folks who designed the markup 

That said, I think our working group should discuss whether we need to 
say anything about cases where the tool might have "partial" information 
about the function of an image (e.g., because it asked for the user's 
photo, because a photo was added to an album titled "My trip to Rome", 
etc., etc.).


Henri Sivonen wrote:
> I cannot find advice in ATAG 2.0 or the Techniques document on what an 
> HTML 4.01 generator that presents user-supplied images should do about 
> alt text when the user hasn't supplied a text alternative for the image. 
> (Consider for example a media sharing site that allows batch upload of 
> digital photos. The HTML generator should be able to emit valid HTML 
> 4.01 regardless of user input or lack thereof.)
> I propose this case be addressed, or if it already is, making the advice 
> more locatable.

Jan Richards, M.Sc.
User Interface Design Specialist
Adaptive Technology Resource Centre (ATRC)
Faculty of Information (i-school)
University of Toronto

   Email: jan.richards@utoronto.ca
   Web:   http://jan.atrc.utoronto.ca
   Phone: 416-946-7060
   Fax:   416-971-2896
Received on Wednesday, 20 August 2008 13:48:05 UTC

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