[Lots of quotes trimmed. Thank you for the explanations why alt
absence recovery is not a priority for AT vendors.]
On Sep 26, 2007, at 03:22, John Foliot wrote:
Henri Sivonen wrote:
Yet, I often get a feeling that arguments based on the current state
of AT (JAWS in particular, sometimes WindowsEyes--everyone expects
VoiceOver to be a moving target) have an implied premise that AT is
what it is and as good as it gets. Sometimes it seems like the state
of AT is taken as the most rigid piece in the overall Web ecosystem
to the point of suggesting that browsers, authoring tools and
countless authors change instead.
I believe that it has been repeatedly pointed out that Adaptive
Technology
is not an User Agent (browser).
I'm unsure why you tell me this at this point.
It has been explained to me why the AT upgrade cycle is slow. But it
doesn't explain the general defeatist attitude towards AT R&D that I
often sense in discussions.
It is not defeatist, it is realistic.
FWIW, acknowledging that there are markup generator situation where
the generator does not have alternative text available is also
realistic.
The word "reliable" is the problem.
All too often in these accessibility debates it is taken as a given
than someone else has to provide something reliable (or "unambiguous"
or something like that). You don't get "reliable" from an
uncooperative data source, which the Web is from the point of view of
an AT UA.
How reliable is a void?
100%. You know for certain that you did not get a useful alternative
text.
Allowing the void to exist in the spec
perpetuates the ambiguity, with the added downside of signaling to
the world
that alt text is really not critical, and in some instances can be
avoided.
I'm referring back to "realistic" above. Even if you vehemently
signal "critical", there will be image data coming from somewhere and
going to the Web without associated alternative text coming with it.
That's what markup generators have to work with. If you don't allow
them to be honest and say "I don't have that data to go with this
image", they will lie.
No, I don't think we have yet come to the conclusion that the absence
of data will continue to be worse than bogus data.
I would suggest that most of the accessibility community are pretty
much in
unison with Steven's assertion, it is you that have not yet agreed
to what
it is we are saying: something - anything - is better than nothing.
No, what I have seen is an implication that the kind of somethingness
of reading the file name is not deemed systematically better than the
nothingness of reading the empty string.
This should be
trivially true: If a consumer prefer bogus data over absent data,
bogus data can (by definition) be generated out of thin air. OTOH, if
a consumer prefers absent data over bogus data, telling bogus and
non-
bogus data apart is harder.
...and how are you going to do this when all that is supplied is
<alt src=""
/>?
I am unaware of the expected semantics of the example.
You've just confirmed what we've been saying all along - there
needs to
be some sort of mechanism that signals something about the image.
Without a
specific "hook", the best you can achieve is a coin toss - a 50%
chance of
guessing right (it should have alt text, it shouldn't have alt
text). The
hook is, and should remain, the alt attribute.
Moving the coin toss away from the client where you can't observe it
may look like a solution but isn't. If whichever party you move the
responsibility of signaling to lacks information, you still get a
coin toss.
AT UAs need to deal with those cases, too, though. The question is,
really, whether explicit flagging as "critical" has enough value
compared to falling in the same bucket with lack of alt for unknown
reason.
With the flag, the chance of "reliability" increases multi-fold -
at least
we know "something", even if ultimately it is of little usable
value to the
end user: we know that it is an image that *should* have
alternative text,
but doesn't.
Suggestion: If alt="" is reserved for images without the need for
a value,
then perhaps there should be another reserved value that signals
that an
image *should* have alternative text, but doesn't. That certainly
would be
more reliable than a 50/50 guess, no?
That's something very different than merely vehemently insisting on
*some* alt, *any* alt, as a matter of principle. That's potentially a
good idea.
See also:
http://lists.w3.org/Archives/Public/public-html/2007Sep/0150.html
http://lists.w3.org/Archives/Public/public-html/2007Sep/0286.html
Henri, on this one, just say "Oops, yes that's true".
Oops. I'm looking forward to the results of interviewing users.
Now, I'm going to go write some software.
--
Henri Sivonen
[EMAIL PROTECTED]
http://hsivonen.iki.fi/
