W3C home > Mailing lists > Public > public-comments-wcag20@w3.org > December 2005

Reasonableness of baselines

From: Jason White <jasonw@ariel.its.unimelb.edu.au>
Date: Sun, 11 Dec 2005 19:05:11 +1100
To: public-comments-wcag20@w3.org
Message-ID: <20051211080511.GA6370@jdc>


There are important reasons why WCAG 2.0 should not establish a baseline or
set of baselines. 

Firstly, if baselines were specified in WCAG 2.0, the
document would become outdated, more or less rapidly as Web standards and
software implementations evolved. 

Secondly, different baselines are appropriate to different circumstances and
user populations. For example, organizations providing user agents to their
employees, or governments with social welfare policies that fund the purchase
of hardware and assistive technologies, are in a stronger position to support
the adoption of newer technologies by end users, and this should be reflected
in the baselines considered appropriate under those conditions.

Thirdly, the decision not to specify any baselines in WCAG 2.0 itself
supports technical innovation by offering an incentive, namely that of WCAG
2.0 conformance, to the use of new and emerging technologies in ways that
enhance accessibility. By contrast, the fixing of a baseline in WCAG 2.0 would
retard technological progress, especially if this baseline were adopted for
regulatory purposes.

The approach to baselines taken in WCAG 2.0, however, leaves open the risk
that content developers or policy bodies will choose inappropriate baselines.
To minimize this risk, I suggest that criteria be introduced into WCAG 2.0
specifying considerations that must be taken into account in selecting a
baseline. These could be included, for example, in the "baseline" section, or
as a new guideline under principle 4. Although the question of whether an
appropriate baseline has been chosen in any particular case is not reliably
testable, that specified considerations have been taken into account in
arriving at a baseline can be tested satisfactorily. For content authors, it
should be sufficient that either (1) the prescribed considerations have been
taken into account by the developer; or (2) the developer has chosen a
baseline established by an organization that has taken the required
considerations into account.

Suggested criteria that must be taken into account in establishing baselines:

For each technology:

1. The extent and quality of support for the technology in user agents.

2. The extent to which user agents implementing the technology conform to
relevant accessibility guidelines and specifications, including the User Agent
Accessibility Guidelines 1.0 as well as any applicable accessibility API's or
other conventions specific to the operating system.

3. The extent to which user agents implementing the technology support a
variety of user interfaces adapted to the needs of people with disabilities.
(i.e., assistive technologies and alternatives interfaces).

4. The extent to which authoring tools supporting the technology implement the
Authoring Tool Accessibility Guidelines, and the capacity of the developers
who will write the content to implement aspects of WCAG 2.0 not sufficiently
supported by the available authoring tools.

5. The extent to which the technology is backward-compatible with earlier
versions for which better support is available, and the extent to which
content that uses the technology can be presented and operated by software
that doesn't support this technology. (i.e., does it "degrade gracefully"?)

6. The availability, in practice, of user agents supporting both the
technology and accessibility to people with disabilities who may try to
access the content to which the baseline applies.
Received on Sunday, 11 December 2005 08:05:30 UTC

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