W3C home > Mailing lists > Public > wai-xtech@w3.org > February 2008

Re: what's machinable [was: Re: ALT issue redux]

From: Gez Lemon <gez.lemon@gmail.com>
Date: Mon, 4 Feb 2008 19:36:40 +0000
Message-ID: <e2a28a920802041136k27a889e7w1fd90baff388d50@mail.gmail.com>
To: wai-xtech@w3.org

On 04/02/2008, Al Gilman <Alfred.S.Gilman@ieee.org> wrote:
> You hit the nail on the head when suggested that @alt is not the
> only markup pattern we need.  For HTML5 we need to look at how
> a variety of markup patterns can meet the functional requirement
> set out in WCAG2 that there be a textual alternate.
>
> The ARIA @labelledby attribute is one candidate.

Whilst it's easy to understand that @describedby would be a perfect
replacement for @longdesc, it's harder to understand how @labelledby
will prove useful for alternate text, although there may be a few edge
cases. @labelledby would be a perfect replacement for the @for
attribute used with the label element, but to work for images, it
would require that a description is available elsewhere in an element
with an @id specified for the short description. There might be a few
cases where this would work, but when you take out decorative images,
and descriptions that are better be suited to @described by, they
would be very few. Having said all that, I could live with @alt,
@labelledby, or non-empty content being required for conformance.

> The point that I was trying to make in talking about machinable
> stuff is that where a textual alternate is required, the
> association of the text and its non-text alternate needs to
> be clear in the markup semantics.

I'm sure most people that are insisting that an alternate is provided
are flexible on exactly how it is provided-  the point is that they
want to see something required for conformance. At the moment, not
only is no method at all required for conformance, but the draft
outlines circumstances where it's considered unreasonable for an
author to provide an alternate for non-text content; that isn't
acceptable, and is what should be immediately addressed by WAI. It's
understandable to allow them the creativity to address the problem,
providing there is insistence that they do actually address the
problem.

> One of my FAQs is that "The people with the answers see the world
> through a more fine-grained reticle (system of sorting categories)
> than do the people with the questions."

That should be both a great comfort to those who think they know the
answers, and those of us that ask the questions. I hope part of the
FAQ is to ensure those who know the answers take time to make sure
they understand the questions.

> You are right there are different requirements in the different use
> cases.  And my current thinking is that @alt doesn't meet all the
> requirements
> and would be awkward to try to stretch that attribute to meet them all.
>
> For example in HTML+ARIA we have @labelledby that lets us point by ID
> to something that can contain markup.  Better for i18n, better
> in general than @alt that only can contain a text string, no markup.

Better for @describedby, as a longer description is likely to benefit
from markup. The @alt attribute is supposed to be a concise alternate
if the image is missing, and used in conjunction with a longer
description if necessary. Forcing longer descriptions on people that
might not want them doesn't seem helpful. Do you have other examples
where an alternate for an image wouldn't be appropriate that is better
for internationalisation or anything in general, where the image
should be part of the content?

> aside: I have an un-finished guideline about "me too" messages.  I
> think it helps to have a second voice on record in agreement.  Too
> many can get just contribute to inbox glut.  But it's hard to
> articulate a netiquette principle that will get followed in the
> wild.

+1

Gez



-- 
_____________________________
Supplement your vitamins
http://juicystudio.com
Received on Monday, 4 February 2008 19:36:52 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 13:15:44 GMT