FW: baseline

Hi Shawn and gang

 

OK I think we have some good Baseline explanations going on now.  Loretta
and Gregg were able to tighten up some of our baseline discussion. 

 

Here's a short answer to the question. Why can't someone just make up any
absurd baseline they want?

 

1)      If the person is required to make their site accessible - then the
person or agency that set the requirement should have specified an
appropriate Baseline.  So the person can't set their own that defeats
access.

 

2)      If the person is NOT required to make their site accessible - then
they could set an unreasonable baseline - is true.  But they could also just
do nothing -  or anything they want.  Presumably someone who voluntarily is
making their site accessible, would choose one of the recommended Baselines
that are known to support accessibility.   But if there are no requirements
then there are no requirements. 

 

 

More below.

 

What is Baseline?

 

A baseline is a set of technologies (e.g. HTML, CSS, etc) that are supported
by user agents (e.g. browsers and assistive technologies).  When an author
cites a baseline when making an accessibility claim, the author basically is
saying that "These pages conform to WCAG 2.0 for user agents (including AT)
that support the technologies in the baseline.

 

If an author says "this page conforms to WCAG 2.0 at level double-A (AA)
with a baseline of HTML, CSS and .avi (movies), they are saying that their
page meets WCAG 2.0 if viewed through accessible  user agents that support
HTML, CSS and .avi movies. 

 

 

Why introduce the idea of Baselines in WCAG 2.0? 

 

All guidelines have baselines.  In WCAG 1.0 the assumed baseline was HTML
(minus client side image maps, frames, auto-refresh, and deprecated
features)) and common movie formats that supported closed captions.   But
because the baseline was built directly into the guidelines, it was not
possible to change the baseline as user agents and AT advanced.   When AT
supported CSS 1.0, it was still required to make pages accessible without
it.   When PDF became accessible (if done properly and with certain
limitations), it still was not possible to meet WCAG 1.0 using it.  When AT
supported frames, you still had to meet WCAG 1.0 without frames.   As a
result, WCAG 1.0 became dated very quickly.   It also had to be written with
13 "until user agents" clauses, which in effect said "use this baseline
until user agents change, and then use another baseline". 

 

In developing WCAG 2.0 the Working Group was faced with even faster
developing technologies and a requirement for a set of guidelines that would
not quickly go out of date.  However, the Working Group also needed to
provide effective accessibility for the state of technology available to
users today.  So the choice was  a) create guidelines that quickly become
obsolete, b) create guidelines that are not meaningful until the future, or
c) create guidelines that describe how to make web content accessible, but
do not tie themselves to particular technologies or technology support.
This latter approach (#3) is not as concrete as the first two but is the
only one that was realistic given the need for guidelines that work today
and for awhile.  The concept of the baseline was introduced to allow the
state of evolving user agent support to be evaluated separately from the
principles of accessibility outlined in the guidelines.   The principles
stay the same but as technologies evolve the baseline can be adjusted to
accommodate new technologies as they are made accessible.  Techniques then
describe how to accommodate them in a way that is compatible with user
agents including assistive technologies. 

 

So if there is no Baseline set in WCAG 2.0 itself, who sets the baselines?  

 

Baselines should be set by organizations that are responsible for providing
content, by those purchasing content, or by those responsible for the
welfare of Web users.  A government may set a baseline in connection with
accessibility regulations for content made available to its citizens. These
baselines can then be updated over time as technologies change without
having to redefine all the rules.   A baseline could be recommended by
organization such as WAI based on an evaluation of user agent capabilities
and availability.  Or it could be established by anyone purchasing Web
content or services.  For example a purchase contract may include a line
that says "Content must be WCAG 2.0 double-A conformant assuming a baseline
of HTML 4.01, CSS and  XYZ movie format."     A company could set a baseline
for use with its intranet that is based on the user agents that it provides
for its employees. 

 

And would baselines be determined?

 

Those setting a baseline should evaluate the existing Web technologies to
see which ones are supported by user agents including Assistive
Technologies.  Those technologies that are supported would be included in
the Baseline.  For content that is used strictly within a company, a
baseline may be different than for content that is meant to be viewed by the
general public since a company may be able to provide more advanced
technology to its employees than would be generally available to the public.


 

 

What prevents an Author from setting the baseline to technologies that are
not supported by AT?

 

If there are regulations or policy that requires the author to follow WCAG
2.0, that policy should also state what the level of WCAG 2.0 would be and
what the baseline should be.  In the absence of policy or other
requirements, an author is not required to follow WCAG 2.0 at all or to use
any particular baseline.  Those authors that voluntarily follow WCAG will
generally not select an unreasonable Baseline. 

 

When authors say that they are WCAG 2.0 conformant, they must say what their
baseline is.  If it contains technologies that are known to be not
accessible to AT then one can tell from the baseline that the site is not
very accessible.   Without policy, or known and accepted baselines, this can
happen.   The development and adoption of good baselines will therefore be
important and should be done at the same time that WCAG 2.0 comes out. 

 

Will the WCAG Working Group set any baselines to go with WCAG 2.0? 

 

The Working Group does not plan to set any baselines.  It will be creating
some sample or reference baselines, based on user agent and AT support of
technologies. As user agent support evolves, these reference baselines will
need to be updated periodically.