W3C home > Mailing lists > Public > public-html-a11y@w3.org > August 2010

[Bug 10455] Mint a describedby attribute for the img element

From: <bugzilla@jessica.w3.org>
Date: Mon, 30 Aug 2010 17:42:57 +0000
To: public-html-a11y@w3.org
Message-Id: <E1Oq8Nl-00061N-Rm@jessica.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=10455





--- Comment #28 from Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>  2010-08-30 17:42:57 ---
(In reply to comment #25)

> * I am open to changing the attribute's name

 It is hardly useful to document @longdesc support if you suggest a new name --
so I assume that in reality, you are open to the name @longdesc. (That's at
least the only thing I'm open to.)

> * My Research so far on Longdesc Examples In the Wild:
> http://www.d.umn.edu/~lcarlson/research/ld.html

(a) the list of  #redundant examples: How useful is it, for a user of JAWS
(which supports @longdesc) if @longdesc has to be duplicated in a redundant
anchor element? Please keep in mind that the only announcement JAWS seems to
make is "Press enter for long description". Thus, the user might not realize
that the @longdesc as well as the redundant anchor link, leads to the same
place. If the longdesc link really has to be invisible and available only to
screenreader users, then using an invisible image map that is accessible to all
of them, without duplication, could possibly be better than having to use
@longdesc *and* and additional link as well.

(b)  the list of  #redundant examples is too short:  All these examples
redundant anchor links in addition to @longdesc:

  1) all the CSSsquirrel's comics examples
  2)
http://www.fdic.gov/regulations/examinations/supervisory/insights/siwin09/Interest_Rate_Risk.html 
  3)
http://doe.k12.hi.us/specialeducation/SpEdHandbook2006/06appendix_a.htm#SeizureAlgorithm
  (The first @longdesc URL is invalid, while the image is wrapped in an anchor
element with a working URL.)
  4)
http://www.hse.gov.uk/aboutus/strategiesandplans/hscplans/strategicplan0104/plan0104-09.htm#httpwwwhsegovukaboutusstrategiesandplanshscplansstrategicplan0104plan010409longdeschtmLongdescriptionavailable
  4) http://ntl.bts.gov/lib/jpodocs/repts_pr/13669/section03.htm

(c) CSSsquirrel's use of @longdesc raises many questions:

     *  He uses it to link to a transcript. His @alt text, however, is just a
single word .... Has the @longdesc become an escape for a good @alt text? Apart
from Episode #72, could he just have used @alt for his transcripts? Or, if he
used <object> instead of <img>, could it have been inside the fallback? Or,
perhaps the @alt should have been empty – with a visible transcript link for
all? Please note that @longdesc, according to HTML4, always works in tandem
with an @alt text. This is the DTD definition: -- link to long description
(complements alt) --.  Thus, if there is no useful @alt, then it does in
principle not seem justified to add a @longdesc.

     * According to you -
http://lists.w3.org/Archives/Public/public-html-a11y/2010Aug/0190 - a table can
be a bad WCAG longdesc description for a diagram. And a transcript is possibly
a bad WCAG longdesc description of a cartoon, as well. This is at least true
for CSSquirrel's Comic #72 - a non-sighted user will not understand what the
humor in the image of episode #72 is about, as there is not description of the
image! Ironically, it is the _transcript_ that is lacking, since that image is
an image of some words  - obviously those words should have been provided as
@alt text.

     * But if, for Comic #72, CSSquirrel had chosen to add a "real" WCAG
longdesc description, then he could EITHER have created a new, separate
document with that description. OR he could add it to the existing transcript.
In the latter case, should he then just use @longdesc to pont to the WCAG
londesc description part of the document? And another link to point to the
transcript part of the documetn? My answer is: why not. It is definitely a
possibility. THus, two links: one linke to a transcript. And another one to the
longdesc document. Voila: we get to use a link and a @longdesc simultaneously.
Excellent, in my view.

However, often an author will not do that. Often an author will only provide a
transcript in some form - possibly with some vague image description. In that
case, what is the best way to link to the transcript? If we forget the problem
of whether the link should be visible to sighted or not, would it best for the
non-sighted to know that it is a transcript? Or should he be told that it is a
long description? In other words: rel="longdesc" or rel="alternate" (or, if
someone defined its meaning, rel="transcript")? To put it another way: very
often something like rel="transcript" would be useful. And not only to the
sighted. (For my own part, I tend to read his transcripts more thorougly  than
his cartoons.) ;-)

Statement: the choice between rel="longdesc" and rel="alternate" is more easily
made if one can use the anchor/area element for both link types. This is not an
argument _against_ @longdesc. I just think that if @rel="longdesc" exists, then
authors' thinking about these things will improve. I think especially the case
that @longdesc links are typically duplicated, is an argument in favor of
adding @rel="longdesc" to the HTML language, so that authors can get the same
feature by use of a normal link.

-- 
Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
Received on Monday, 30 August 2010 17:42:59 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:05:13 UTC