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[techs] checklists, relationships, schema

From: Wendy A Chisholm <wendy@w3.org>
Date: Tue, 11 Feb 2003 14:33:10 -0500
Message-Id: <5.2.0.9.2.20030211135652.010efd48@localhost>
To: w3c-wai-gl@w3.org

Hello,

Michael and I chatted last week about a couple of concrete examples and 
wondered how they would look in an HTML checklist.  Here's an attempt to 
describe some of the issues:

Checkpoint 1.1, Minimum level success criterion 1 says, "non-text content 
that can be expressed in words has a text-equivalent explicitly associated 
with it."

Checkpoint 1.1, Example 1: an image used as a button. (short description of 
function)
A right arrow icon is used to link to the next slide in a slide show. The 
text equivalent is "Next Slide," so that what is read by a screen reader 
would be "link: Next Slide."

Checkpoint 1.1, Example 5: an audio file of a symphony. (short label)
An audio file is embedded in a Web page. The short label says, "Beethoven's 
5th Symphony performed by the Vienna Philharmonic Orchestra."

In the HTML checklist, we expect to have a true/false statement that says 
something like: any image (embedded with the img element) that can be 
expressed in words has a text-equivalent explicitly associated with it via 
the alt attribute.
**Note: there is not consensus that the statements would read like 
this.  This is just an example for demonstrative and discussion 
purposes.  Please feel free to improve the wording.

We have said that every success criterion must have a true/false statement 
so that the user has to check off something for each success criterion [0]. 
This example of a true/false statement would apply to Example 1 but not 
Example 5.

However, since the two success criteria have an "or" relationship, I 
believe it might make more sense for the user to have one checkbox for the 
two ala:

[ true/false]
any image (embedded with the img element) that can be expressed in words 
has a text-equivalent explicitly associated with it via the alt attribute.
OR
any image (embedded with the img element) that can not be expressed in 
words has a descriptive label provided as its text- equivalent via the alt 
attribute.

However, for a conformance claim, you will want to have checks for each 
success criterion.  But, is it easy to understand the following (using 
Example 1 as the example)?
[ true ] any image (embedded with the img element) that can be expressed in 
words has a text-equivalent explicitly associated with it via the alt 
attribute.
[ false ] any image (embedded with the img element) that can not be 
expressed in words has a descriptive label provided as its text- equivalent 
via the alt attribute.

What about the longdesc attribute and other forms of description?
[true/false] any image (embedded with the img element) that can be 
expressed in words has a text-equivalent explicitly associated with it via 
the longdesc attribute.

This is additional to the first statement (marked as true).  Thus, we have 
a variety of relationships:  AND, OR, and additional.  How does the 
"additional" map back to the checkpoints and success criteria?  In this 
example, it seems to map back to the first success criterion, but with an 
"additional" relationship.

Summary and questions:
- success criteria seem to have at least 3 types of
    relationships: and, or, and additional (or "stacked").
    What about the "at least one of" type as in   2.2 [1]
    What about exceptions as in checkpoint 1.2 [2]?
- how does html:longdesc map back to checkpoint 1.1?
-  How do we want to deal with these relationships and
    mappings in our xml?  We had some discussion last
    week about internal data vs external metadata to
    describe the relationships. Similar debate to using
    internal style sheets vs external. If external only have
    to fix changes in one spot.
- what will the true/false statements for techniques look
    like?  are the examples given above similar to what
    people have had in mind? if not, please provide examples
    of what you've been expecting.
- i would like to see more concrete examples used in discussion.

--wendy

[0] http://www.w3.org/TR/wcag2-tech-req/#req-checklists
[1] http://www.w3.org/WAI/GL/WCAG20/#avoid-interfering
[2] http://www.w3.org/WAI/GL/WCAG20/#time-based

-- 
wendy a chisholm
world wide web consortium
web accessibility initiative
http://www.w3.org/WAI/
/-- 
Received on Tuesday, 11 February 2003 14:33:20 GMT

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