ATAG2 B.2.4 Assist authors to manage, edit, and reuse equivalent alternatives for non-text objects.

Hi all,

We were discussing B.2.4 on the call last week and I also have just  
remembered this exchange with Henri  
(http://lists.w3.org/Archives/Public/w3c-wai-au/2008JulSep/0083.html)

Part of the problem was that we had a note that says "Note: Equivalent  
alternatives should not be automatically generated from unreliable  
sources (e.g., file names should not be used as text alternatives)."  
but if this is normative it should be an SC.

Trying to take these things into account, I propose a fairly extensive  
rewording:

B.2.4.1 Existing alternatives: If the authoring tool suggests existing  
alternatives for author-selected non-text objects (e.g., previous  
author entry, description from an image database description), provide  
authors with the opportunity to accept, modify, or reject the  
alternatives, prior to insertion. (Level A)

B.2.4.2 Automatically generated alternatives: If the authoring tool  
has the option of automatically generating alternatives for  
author-selected non-text objects, both of the following must be true  
(Level A):
- only alternatives that result from audio and/or video analysis of  
the actual objects is acceptable (e.g., speech recognition). Use of  
unreliable information (e.g., the file name, arbitrary numbering) is  
not acceptable.
- authors are provided with the opportunity to accept, modify, or  
reject the alternatives, prior to insertion.

B.2.4.3 Meaningful Null Values: If a technology includes guidance on  
null values (e.g., in HTML4, alt="" has a different meaning than no  
alt attribute), follow this guidance (Level A).

B.2.4.4 Save for Reuse: Provide authors with the option of having  
*recognized* plain text text alternatives that they enter (e.g.,  
alternative text labels, long text descriptions) stored and then  
offered for reuse in the future (Level AA).

Applicability Note:
- This guideline does not apply to non-text objects that are  
automatically added by the authoring tool. These are covered by  
Guideline B.1.3.

Received on Sunday, 9 November 2008 14:33:11 UTC