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Re: Warnings about access info loss (MS21)

From: Richards, Jan <jrichards@ocad.ca>
Date: Tue, 9 Nov 2010 23:39:47 -0500
To: "w3c-wai-au@w3.org" <w3c-wai-au@w3.org>
Message-ID: <F2C77FB59A1A4840A01EF5F59B1826E20A283A8C7A@ocadmail.ocad.ca>
What about splitting things out a bit to be more specific and using the sub-types of transformations as specified in our def'n?:

UNCHANGED: web content transformation: A process that takes as input, content in one web content technology or non-web content technology (e.g., a word processing format) and produces as output, web content that has been *restructured* (linearizing tables, splitting a document into pages), *re-coded* (e.g., HTML to XHTML, a word processing format to HTML) or *optimized* (e.g., removing whitespace, re-compressing images).

CHANGED: accessibility information (WCAG): Any information that web content is required to contain in order to meet the WCAG 2.0 success criteria at a particular level. For example, text alternatives for non-text content, role and state information for widgets, relationships within complex tables, captions for audio.

Optimizations Preserve Accessibility: If the authoring tool provides "optimizing" transformations then any *accessibility information (WCAG)* in the input is preserved in the output. (Level A) 

ed: so optimizing transformations should never result in lose accessibility info.


Text Alternatives Preserved: If the authoring tool provides transformations that preserve non-text content, then text alternatives for the non-text content are preserved if possible in the output technology. (Level A)
Note: This only applies to transformations in which the output technology is an *"included" technology* for conformance.

ed: so if the non-text content is kept, so are the alternatives. Note, these are text alternatives not other accessibility info like ARIA relationships and audio descriptions.


Restructuring and Recoding Transformations (WCAG): If the authoring tool provides "restructuring" or "re-coding" transformations, then at least one of the following is true:
Note: This only applies to transformations in which the output technology is an *"included" technology* for conformance.
(a) Preserve: accessibility information (WCAG) is preserved in the output; or
(b) Warning: authors have the default option to be warned that accessibility information may be lost (e.g., when saving a vector graphic into a raster image format); or
(c) Checking Active: accessibility checking is active on the output; or
(d) Checking Suggested: authors have the default option to have accessibility checking suggested.

Level=3 levels of WCAG

Ed: so if the tool can't simply preserve the accessible info, the other options are all different ways of the author finding out the severity of the problem.



Cheers,
Jan
Received on Wednesday, 10 November 2010 04:40:09 GMT

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