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WCAG 2.0 - November draft - Overall Suggestions on Principles, Gu idelines, Conformance, Success Criteria, Techniques and Checklists

From: Catherine Brys <c.brys@lib.gla.ac.uk>
Date: Mon, 10 Jan 2005 16:48:12 -0000
Message-ID: <185CACB1E3412746A381E4E026529BDCBC0A90@exchange-l.lib.gla.ac.uk>
To: "'public-comments-wcag20@w3.org'" <public-comments-wcag20@w3.org>

[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.

oo Overall Suggestions on Principles, Guidelines, Conformance, Success
Criteria, Techniques and Checklists
- Some principles are so general that they are rather vague and difficult to
Principle 1: Content must be perceivable. What does 'perceivable' mean? How
can content be *not* perceivable?
Principle 2: Interface elements in the content must be operable.  What does
'operable' mean? How can content have interface elements? What are they?

- Principle 4: Content must be robust enough to work with current and future
How can future technologies be taken into account? It is quite impossible
for every web author to be able to anticipate how user agents will evolve.
It would require too much technical knowledge - if predicting future user
agents is at all possible.

- Why has the terminology of the Web Content Accessibility Guidelines 1.0
been abandoned? This will confuse a lot of people. The term 'priorities' is
much clearer than the term 'success criteria'. Why success criteria levels
1,2,3 and conformance levels A, double-A and triple-A rather than the
existing terminology? The entire web content accessibility guidelines and
conformance levels are quite hard to understand for a lot of people who are
not involved on a day-to-day basis. I think it is important that these
people can have a basic understanding of the guidelines and conformance

- Success Criteria:
It would be much clearer if the requirements under success criteria (and
supporting information) would be worded as requirements using the word
'must' rather than as statements. The current wording suggests that the
desired effect has already been achieved - or worse - suggests a general
Example of success criteria: 
.. "Level 1 Success Criteria for Guideline 1.2
If multimedia content is rebroadcast from another medium, the accessibility
features required by policy for that medium are intact."
Examples of supporting information: 
.. "Who Benefits from Guideline 1.4 
Individuals with low vision can easily read characters in the content even
if they don't have the wide field of view or full range of colour perception
used by fully sighted persons to separate text from background images." 
This can be interpreted by the careless reader as that individuals with low
vision can always easily read characters in the content. Please make it
clearer that this is only true if the guideline is adhered to.
.. The 2 sentences under 'Who Benefits from Guideline 2.2' are not parallel
in meaning: the first sentence is a general truth; the second is only true
if guideline 2.2 is adhered to.
.. "Who Benefits from Guideline 2.3
Individuals with photosensitive epilepsy can avoid having seizures triggered
by flashing or by spatial patterns." If the heading is skipped (and most
readers scan when reading), the sentence reads as a general truth. 

- I believe the checklists should be normative to make it easier for people
to understand web accessibility.

- I would suggest replacing 'Technology-specific application information'
with 'Techniques'.

- Testability of guidelines: 
Computer programs will never be able to test accessibility guidelines
satisfactorily so should it not be recommended that web pages are checked by
computer programs *and* (not or) people who understand these guidelines?
It is utopic to expect different people to obtain identical results when
testing for accessibility - there will always be a degree of interpretation.

- Conformance - Baseline Technologies Assumption:
I strongly disagree with the idea of assuming a baseline user agent when
drafting the WCAG. The baseline user agent assumption would lead to web
sites which conform to the guidelines but are  in practice inaccessible to
disabled users. One of the excellent aspects of the WCAG 1.0 was that they
gave an insight into how less then perfect user agents work. 
The repair techniques should be an integral part of the guidelines and
following them should be a requirement for conformance claims. Assuming
scripting is available to all end users goes totally against the spirit of
inclusiveness and making the web work for users using less up-to-date
I understand that it would be desirable if the WCAG were more stable but the
way the document is currently evolving will mean that it is far from
practical, too vague, very technical and not taking the real world into
account. This will ultimately lead to a less accessible web.

- Conformance Requirements:
Will allowing people to quote that web pages conform with WCAG 2.0 when they
only meet all *level 1* success criteria not lead to confusion and be
interpreted as that the pages conform to *all* levels? Would it not be
better to require to always specify the conformance level?

- Conformance Claims:
.. Point 2: The way this has been defined seems very complicated and
daunting. Is there not an easier way (and maybe less accurate way if need
be) to express this? A 'URI pattern' is defined in terms of a 'regular
expression', which is not even the commonly used definition of a regular
expression. This makes the guidelines hard to understand for anyone but
specialists in a very narrow technical field. 
The same applies to the definition of 'delivery units': this is quite
What is meant with 'content negotiation'?
.. Why should conformance claims be transmitted in the HTTP header? The HTTP
header does not usually contain content information. 

- Level of conformance being claimed
Is this section really necessary? Is it not too detailed? It does not seem
very clear to me - again very complicated. 
'authored unit is defined as "Some set of material created as a single
entity by an author." What is a single entity in web terms? A paragraph? A
page? A set of pages? Should this set of material be restricted to one

- Scoping of Conformance Claims
Has this not already been covered in 'Conformance claims'? Should the set of
URIs should not cover this?

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 17:27:07 UTC

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