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RE: my first attempt at longdesc

for

From: Jukka Korpela
Date: Sep 25, 2002 12:46AM


Timothy J. Luoma wrote:

> I finally came upon an instance where I thought it might be important
> for the reader to have a long description of what was, for
> viewers with no visual impairments, better served with an image.

I would say "an external equivalent" rather than "a long description", but I
understand that you're using the terminology that is natural if we take the
attribute name longdesc literally. But we need to be careful then.

After all, a longdesc should apparently point to a text _equivalent_ at some
address, instead of an equivalent to be used in place of the image. So when
you use longdesc, it's normally the longdesc text that is really the
equivalent and the alt text is just a description. In rare cases, you might
actually want to describe an image (say, a painting) rather than present a
textual equivalent, and in such cases longdesc might, perhaps, be made to
point to a description.

> So it seemed like a good time for me to try LONGDESC
>
> http://tntluoma.com/opera/lover/day23-downloads/
> visit http://www.webaim.org/discussion/

It works fine on Lynx, because the alt text is informative and the image is
a link. So you are not really relying on longdesc (which isn't, after all,
to be much relied on).

However, it doesn't work very well e.g. on IE in a situation where the user
cannot quite see the texts in the image, due to visual impairment. Actually,
I'm sure many people have difficulties in reading the rather small text on
gray background. The image is not indicated as being a link, and there is no
"tooltip text". You have title="". I think it would be better to omit the
title attribute or, better still, use a title attribute with content
identical with, or similar to, the alt attribute value. Then a user who
needs big text and probably has his browser set to use large font could find
out that he can follow the link to see the text better.

I think it might be easier to use a normal textual link to the long
explanation. You could still have a longdesc pointing to it, of course. It
is true that an explicit link might be slightly disturbing in situations
where it is not needed. But sometimes a creative idea can avoid this. For
example, maybe you can use a caption for an image and make that caption a
link. For some notes on such approaches, see
http://www.cs.tut.fi/~jkorpela/html/alt.html#parallel

Less importantly, the document pointed to by the longdesc attribute (and/or
an explicit link to "long alternate text") could be written using such HTML
and CSS that it logically and visually imitates the content of the image. My
point is that the document is not only for blind people, though it surely
should work for them too. But, of course, this is much less important than
making the information accessible in the first place.

--
Jukka Korpela, senior adviser
TIEKE Finnish Information Society Development Centre
http://www.tieke.fi/
Diffuse Business Guide to Web Accessibility and Design for All:
http://www.diffuse.org/accessibility.html


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