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WCAG 2.0 - November draft - comments re. Aim and Audience of the WCAG

From: Catherine Brys <c.brys@lib.gla.ac.uk>
Date: Mon, 10 Jan 2005 16:46:39 -0000
Message-ID: <185CACB1E3412746A381E4E026529BDCBC0A8C@exchange-l.lib.gla.ac.uk>
To: "'public-comments-wcag20@w3.org'" <public-comments-wcag20@w3.org>
Cc: "'fabien.vais@videotron.ca'" <fabien.vais@videotron.ca>

[based on comments relating to the July draft and submitted originally as an
anonymous contributor on 23 Nov 04]
Disclaimer: The comments below represent the personal opinion of the sender;
they do not necessarily represent the University's viewpoint.


I really appreciate the hard work of the WAI group - sorry if the list of
comments seems daunting. The guidelines are an invaluable tool in making web
sites accessible and promoting accessibility to a wider audience. Keep up
the good work! 

Have divided comments into:
oo Aim and Audience of the WCAG
oo Scope of the WCAG
oo WCAG Structure
oo Terminology and Writing Style 
oo Overall Suggestions on Principles, Guidelines, Conformance, Success
Criteria, Techniques and Checklists
oo Detailed Suggestions on WCAG Content
oo Minor Suggestions
Each section is sent as a separate email.


oo Aim and Audience of the WCAG
I am concerned that as the WCAG are evolving, they are becoming more and
more technical in nature and as a result harder to understand for web
authors. The danger is that:
(a) web authors may misinterpret certain aspects of the guidelines and build
web sites which are not accessible.
(b) more and more people may think that web accessibility is too difficult
to achieve and not something they should bother with.
In both cases, the result will be less accessible web sites. 

The WCAG state that their aim is to explain how to make Web content
accessible and that they have been written to meet the needs of many
different audiences. 
"Abstract
....It has the same aim [as the WCAG 1.0]: to explain how to make Web content
accessible to people with disabilities and to define target levels of
accessibility. Incorporating feedback on WCAG 1.0, this Working Draft of
version 2.0 focuses on guidelines. It attempts to apply guidelines to a
wider range of technologies and to use wording that may be understood by a
more varied audience."
"Audience
These guidelines have been written to meet the needs of many different
audiences, from policy makers, to managers, to those who create Web content,
to those who write the code. Every attempt has been made to make the
document as readable and usable as possible while still retaining the
accuracy and clarity needed in a technical specification."

I am afraid that WCAG are veering further and further away from this aim. I
understand that the WAI wishes the WCAG to be as stable and general as
possible but is the original aim not being lost out of view?

Some examples of terminology:
(definitions taken from Appendix A Glossary)
.. "URI pattern
A URI pattern is a regular expression identifying a set of resources. A
resource belongs to the set if the regular expression matches its URI."
.. "regular expression
A regular expression as defined in XML Schema Part 2: Datatypes, Appendix
F."
.. "delivery unit
A set of material transfered between two cooperating web programs as the
response to a single HTTP request."
.. "lines which are within 500% +/- of the stem width of the characters "
.. "background sounds are at least 20 decibels lower than the foreground
audio content"
.. "general flash threshold
A sequence of flashes or rapidly changing image sequences is not permitted
when both the following occur: the combined area of flashes occurring
concurrently (but not necessarily contiguously) occupies more than one
quarter of any 355 x 268 pixel rectangle anywhere on the displayed screen
area when the content is viewed at 1024 by 768 pixels and there are more
than three flashes within any one-second period. 
Note:
For the general flash threshold, a flash is defined as a pair of opposing
changes in luminance (i.e., an increase in luminance followed by a decrease,
or a decrease followed by an increase) of 20 candelas per rectangle meter
(cd.m-2) or more and where the screen luminance of the darker image is below
160 cd.m-2. "
.. "red flash threshold
A transition to or from a saturated red at any luminance level is not
permitted when both of the following occur: 
the combined area of flashes occurring concurrently occupies more than one
quarter of any 355 x 268 pixel rectangle anywhere on the displayed screen
area when the content is viewed at 1024 by 768 pixels and there are more
than three flashes within any one-second period. 
Note:
For the red flash threshold, a flash is defined as any pair of opposing
transitions to or from a saturated red at any luminance level. "
.. "content negotiation"


Dr. Catherine M. Brys
Library Web Services Administrator
- Library Web Site Accessibility and Usability Project - 
Glasgow University Library, Hillhead Street, Glasgow, G12 8QE, Scotland, UK
e: c.brys [at] lib.gla.ac.uk
t: +44 (0)141 330 6748
w: www.lib.gla.ac.uk/accessible
Received on Monday, 10 January 2005 17:27:04 UTC

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