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Highlights from 161704 Telecom

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Fri, 18 Jun 2004 22:36:40 -0500
To: <w3c-wai-gl@w3.org>
Message-ID: <auto-000073061044@spamarrest.com>

Highlights from 161704 Telecom

Today's Telecom dealt with scoping and its application both within success
criteria and as a general conformance tool. In conjunction with the
discussion, three types of scoping were proposed and are here defined to
facilitate discussion.

Vertical Scoping

Has to do with applying or excluding the WCAG guidelines and success
criteria to particular parts of a website.  If you think of all of the pages
or virtual pages of a website being arranged side by side, vertical scoping
would talk about a particular section of those web pages as conforming or
not conforming. For example, all of our website conforms, except for our
archives and the downloadable books in our bookstore.

Horizontal Scoping

Horizontal scoping refers to particular elements that occur across the
pages. An example of horizontal scoping might say that our website conforms
to the web content accessibility guidelines except all of the images (or all
of the audio, or all of the movies, etc.). Horizontal scoping can have the
effect of removing entirely either guidelines or success criteria and may
therefore, be a problem.

Source Scoping

This relates to discussing the parts of the site that conform or not in
terms of where they came from. An example might be, all of our website is
accessible except for submissions from our members (or except for the
advertisements on each page). Another example might be that our distant
education software conforms to WCAG 2.0 Level 2 except for the content
actually put into a site by the authors/teachers/students/etc. Source
scoping can either be horizontal or vertical, but would generally, it would
tend to be more horizontal in nature.

Reasons for Including Scoping in our Success Criteria

We walked through all of the guidelines and success criteria to try to find
places where we had put scoping like language directly into the success
criteria. This would include places where we said that such a guideline
should be done,. except for the following types of content. Or where we said
that the guidelines should be applied to all content that was of a
particular type or character. We then looked at the reasons why we had added
these exceptions into the guidelines. In general, it turned out that we had
added them for one of four reasons:

1) That the guideline was impossible to apply to certain types of content,
and an exception was therefore made. 

2) Applying the guideline would destroy the function of the content (E.g.,
providing captions to the audio track of a spelling test).

3) Applying the guideline would be counterproductive 
(E.g., providing a means to skip over one or two navigation links at the top
of the page. It would be more work to navigate the skip navigation links
than it would be to just step over the two links 
Example two would be providing a table of contents for a letter that is only
a paragraph or two long.). 

4) It wasn't useful or wasn't important enough to apply this to a particular
(An example would requiring that structured or alternate presentation
mechanisms be provided for a one page two paragraph letter.

Description of Scoping Needed

It was also mentioned that in the guidelines or in support documents we need
to have a good description of how scoping is intended to be used and also,
our rationale for the design of scoping and how that should inform
regulators or anyone using our guidelines to manage accessibility. 

It's important that any regulations allow scoping to be used as we intended
it to or else our guidelines will be too strict.

It is also important that it not be used in ways that were not intended, or
the guidelines could be completely circumvented. 



Gregg C Vanderheiden Ph.D. 
Professor - Depts of Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 
<http://trace.wisc.edu/> FAX 608/262-8848  
For a list of our listserves http://trace.wisc.edu:8080/mailman/listinfo/ 
Received on Saturday, 19 June 2004 02:38:29 UTC

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