W3C home > Mailing lists > Public > public-html@w3.org > August 2009

Re: feedback requested on WAI CG Consensus Resolutions on Text alternatives in HTML 5 document

From: Maciej Stachowiak <mjs@apple.com>
Date: Mon, 17 Aug 2009 00:48:49 -0700
Cc: HTMLWG WG <public-html@w3.org>, W3C WAI-XTECH <wai-xtech@w3.org>
Message-id: <161D06EE-FEE1-418A-8F24-3EE4CD343CF8@apple.com>
To: Henri Sivonen <hsivonen@iki.fi>

On Aug 17, 2009, at 12:30 AM, Henri Sivonen wrote:

> On Aug 17, 2009, at 10:11, Henri Sivonen wrote:
>
>> * "After the end of an authoring session, the authoring tool does  
>> not attempt to repair alternative content for non-text content  
>> using text content that is equally available to user agents (e.g.,  
>> the filename is not used)." (Quoted from ATAG 2)
>>
>> * Autogenerated alt="image", alt="" and alt=" " violate the ATAG 2  
>> language quoted in the previous point.
>>
>> * Autogenerated alt="photo" might be spun not to violate it but  
>> practically isn't materially different from alt="image".
>>
>> * Autogenerated role=presentation doesn't violate the ATAG 2 point  
>> literally but does in spirit.
>
>
> * If @title is considered to function as a substitute for alt in the  
> absence of alt, the same autogeneration considerations apply to  
> @title as well.
>

If that's so, then HTML5 is in conflict with ATAG2, as applied to  
authoring tools.

My interpretation, on studying ATAG2 more closely: I do not believe  
the use of title to describe an image whose contents are unknown would  
meet the ATAG2 definition of "alternative content":

<http://www.w3.org/TR/ATAG20/#def-Equivalent-Alternatives>
"Content that is used in place of other content that a person may not  
be able to access. Alternative content fulfills essentially the same  
function or purpose as the original content..."

In such a case, the title does not have the "same function or purpose  
as the original content", rather it is a best-effort attempt to  
provide *something* given the lack of a proper alternative.

ATAG2 only allows alternative content to be autogenerated if the  
author is given the opportunity to accept, modify or reject. But it  
doesn't have such a requirement for textual descriptions that are not  
alternatives.

I am not sure if this reasoning is in the spirit of ATAG2. For that  
matter, I am not sure if the HTML5 approach will lead to good  
accessibility outcomes compared to the alternatives. But that is my  
reading of the letter of the relevant specs.

Regards,
Maciej
Received on Monday, 17 August 2009 07:49:37 UTC

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