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Re: Empty alt tags

From: <jukka.korpela@tieke.fi>
Date: Fri, 22 Feb 2002 16:43:04 +0200
To: W3C WAI-IG list <w3c-wai-ig@w3.org>
Message-ID: <OFFF992F51.967CA115-ONC2256B68.004EBC73@tieke.fi>

Petri Laatunen wrote:

> alt tag (or attribute or whatever <grin>)

Attribute, definitely. I'm not entirely sure whether the original
question about this was serious or ironic. Anyway, terms matter.
To begin with, if we encourage people into using alt tags, they
will take a look at a list of all HTML tags and find out that
we fooled him. Maybe. So let's use the right terms.

It would be better if we actually had an alt tag, which would be
used to delimit alt elements. This would allow any content, not
just plain text. At present, for example, if an image is a graphic
presentation of an organization chart, you cannot write an alt
text which contains the same information as nested _lists_. You
cannot put list markup into an attribute value. (Besides, due to
poor implementations, alt texts longer than about 50 characters
cause various problems.)

In principle, you could use an <object> element instead of an <img>
element, and you would then put the alternate content inside the
<object> element, and could use e.g. list markup there. And as
much content as desired. In a sense, <object> tag is kind of
"<alt> tag". Too bad it doesn't work at present, at least not
for the purposes of putting images onto Web pages.

> is a way to add a textual
> description for a picture like:
>
> <img src="mypic.gif" alt="some text describing the picture">

Please use the word "alternative" rather than "description" and
"replacing the picture when the picture is not shown" rather than
"describing the picture". I know you know what the idea is, but
it's easy to miss the idea when it is explained in terms of
_descriptions_. It easily results in things like alt="red bullet".
There is a whole collection of very misguided alt texts revealed:
http://ppewww.ph.gla.ac.uk/~flavell/alt/alt-text.html#howlers

> It's useful for those who can't see and are using a screen
> reader to access your pages.

Definitely, but that's just one of the many uses. Other uses
include browsing with images off for efficiency reasons (e.g. when
using handheld devices) and helping search engines to find images.
I have a longer list at
http://www.cs.tut.fi/~jkorpela/html/alt.html#reasons
which might help in explaining the importance of alt attributes.
(It's easy to forget how many reasons there are!)

--
Jukka K. Korpela, erityisasiantuntija / senior adviser
TIEKE Tietoyhteiskunnan kehittämiskeskus ry
Finnish Information Society Development Centre
Salomonkatu 17 A, 10th floor, FIN-00100 HELSINKI, FINLAND
Phone: +358 9 4763 0397 Fax: +358 9 4763 0399
http://www.tieke.fi  jukka.korpela@tieke.fi
Received on Friday, 22 February 2002 09:45:18 GMT

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