[html4all] the alt attribute debate
hsivonen at iki.fi
Tue Sep 25 23:57:32 PDT 2007
[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
> 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
>> 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
> 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
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
>> 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
>> 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
> 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
> 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.
hsivonen at iki.fi
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