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Some comments on conformance levels in UA guidelines draft

From: <peter.b.l.meijer@philips.com>
Date: Mon, 29 Nov 1999 17:35:37 +0100
To: <w3c-wai-ua@w3.org>
Message-ID: <0056890007126293000002L932*@MHS>
First I wish to compliment the people who defined the
User Agent Accessibility Guidelines Working Draft with
their excellent work. A few comments nevertheless, and
I apologize in advance in case my comments have perhaps
already been covered by earlier discussions. Note also
that below I will implicitly be referring only to user
agent accessibility issues for blind users.

As the developer of a user agent that is meant to make 
pure web graphics more accessible to totally blind users
(see the URL below), I foresee several rather fundamental
problems in defining the conformance levels, such as "A", 
"Double-A" and "Triple-A", and in using these to gauge
whether or not my agent complies with these conformance 
levels.

My user agent in practice needs both the basic operating
system features and a "good" screen reader to be "fully
accessible" to blind users. Now some of the necessary 
accessibility features will be provided by the operating 
system, some others by the run-of-the-mill screen reader, 
and still others only by particular brands or versions of 
screen readers, but how far can one stretch this? A vendor
might say that his or her unique owner-drawn graphical items
are readable to blind users if they use third-party OCR 
product X to process a screen capture for his dialog. A 
crude way of working for sure, and hardly user-friendly, 
but it might indeed work according to the rules set by the 
guidelines: no off-screen model is required or involved 
here, and the user can access the information if the right
combination of accessibility tools is bought and used - 
which can also get expensive beyond reason.

The current consensus seems to be that requiring a screen
reader is acceptable, but at some point this does not make
sense anymore. What if one of my user agent's features is 
accessible via screen reader "X" but not via screen reader
"Y", or vice versa. Do I qualify for an "AAA" rating if at 
least one screen reader exists that does the trick? What 
if my feature "a" is handled well by screen reader "X", 
but not by screen reader "Y", while feature "b" is handled
well by "Y" but not by "X"? Can I still get away with it by
just saying that the user should buy both screen readers?
That doesn't "feel" right, of course, but it is unclear to
me where it ends, or where the borderlines are exactly.

Somehow the minimum level of accessibility support provided
by a "good" screen reader (in conjunction with the underlying
operating system) has to be carefully defined first. Without 
that definition of a "reference" screen reader, any accessibility
rating for a user agent relying on what a third party screen 
reader "might" do carries rather little weight, it seems.

Just a simple example: the standard progress bar in Microsoft
Windows. I was recently surprised to find that at least one 
well-known screen reader could not read it out (this was then
confirmed by a blind power user of that particular screen 
reader). The progress bar is certainly displayed as purely 
graphical, but the API system call used by the application 
programmer (me) provides the position and range numbers that 
should suffice to make its reading readily accessible through
a screen reader. So there is no technical reason why the 
progress bar would not be accessible, even though it appears
as purely graphical on the screen. Now step 1 should be that
the operating system indeed makes the progress bar numbers
from the API call available to screen readers, for instance 
via its "off-screen model". Step 2 is that the screen reader
also uses these numbers to render them into an accessible 
representation (e.g., speaking something like "progress 35 
percent" for the default 0 to 100 scale). Step 3 seems to be
that if the screen reader for some reason does not do this 
that the user agent does it instead? Is step 3 necessary if 
at least one screen reader on the market covers it? How does
this affect "my" user agent rating? Right now there are too
many ill-defined dependencies to make the conformance level
or a derived rating work for me.

Please note that I do understand and appreciate the working
groups' encouragement of using only standard operating 
system APIs whenever possible, because that indeed gives 
the best chances that most third party screen readers will 
be able to deal with it. I attempt to practice these 
guidelines myself and in case of doubt try to test things
with one or two screen readers, while end users give me 
feedback if I inadvertently missed something. However, 
"branding" a user agent with respect to conformance with 
the guidelines requires far more strict definitions of what
that conformance entails, because user agent developers 
cannot possibly test their user agent with every screen 
reader (and versions of that) released on the market. 

I'd think the accessibility topic should be covered in two
stages. A clear definition of what an imaginary "reference" 
screen reader would do is required first. Does the reference
screen reader speak standard menu items? Yes. Buttons? Yes. 
Does it speak standard progress bars? I would hope so. So 
we first need a checklist that defines and measures a 
conformance level for screen readers, before we define and 
measure a conformance level of user agents that in practice
often (have to) run "on top of" the combination of operating
system and screen reader.

Perhaps the use (thus risking abuse) of the accessibility
guidelines conformance levels to brand products should be 
strongly discouraged or even forbidden for the time being 
through some explicit working group statements in these
guidelines?

Best wishes,

Peter Meijer


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Received on Monday, 29 November 1999 11:35:42 UTC

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