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Dumb Thought on alt Text (or Smart Thought?)

From: Kynn Bartlett <kynn@idyllmtn.com>
Date: Sat, 2 Feb 2002 01:33:10 -0800
Message-Id: <a05101004b8815e289588@[10.0.1.9]>
To: w3c-wai-gl@w3.org
Cc: "Charles F. Munat" <chas@munat.com>
A dumb thought which I'll share here first instead of sharing on IG:

      Maybe alt text should _only_ be used for images which are
      text-as-graphics.  Everything else gets null alt text.

Okay, expanding on that a little more. The purpose of alt is to be
a textual equivalent/substitution/alternative for an image. The only
textual equivalent for an image is, literally, the text on the image.

So if an image is my name in a fancy font, the alt text is "Kynn".
If it is a picture of me, the alt text is "" (quote quote).  Why?
Because there's no text in there for the alt to be the equivalent
of.

Let's look at a case raised on the IG list earlier this week:

At 9:59 AM -0800 1/31/02, Charles F. Munat wrote:
>Alt attributes are NOT FOR DESCRIPTIONS.
>"Ducks on the lake on a warm summer day" is a DESCRIPTION of the image.
>This makes NO SENSE as alt text.
>The alt attribute text should flow with the rest of the text. After all,
>that is how it will be read. [...]
>Now, suppose that this lake with ducks is right next to Big Hall, and
>that the function of the image is to give visual users a sense of 
>what life is like in Big Hall. Then an appropriate alt text might 
>read: "Big Hall overlooks Campus Lake and its duck denizens."
>Here is how this flows:
>"... There are four residence halls on campus. The biggest is Big Hall,
>located at the northernmost point on campus. Big Hall overlooks Campus
>Lake and its duck denizens. The next biggest is Middling Hall..."

I agree with Mr. Munat's statement that alt attributes are not for
descriptions. I disagree with his next suggestion, though, of hiding
image interpretation within the alt text.

New term: image interpretation. We have "text alternative" which I am
redefining here to be "the text contained with the graphic"; we have
"description" which is "what the picture looks like"; and now we have
"image interpretation" which is "what the image is meant to convey."

It is my suggestion that "image interpretation" is as appropriate for
alt attributes as descriptions, which is to say NOT AT ALL.

Image interpretation should be part of the visible, visually accessible
text of any context in which the image appears. In other words, the
page's visible text content should contain the intended interpretation
of the hall and the ducks, which is the point of the image.

How is this encoded? It should either clearly appear within the page's
textual content in context, or should be associated via markup. There
are few markup methods for doing this reliably; one method which is
barely acceptable is a one-cell data table with a <caption>.  The lack
of clear way to associate interpretive and/or descriptive text with
an <img> is an obvious shortcoming of HTML; this should be passed along
via PF to the HTML Working Group (XLink may help here).

Anyway, so the three ways of giving textual information about an
image would be:

textual equivalent - via alt attribute
description - via longdesc
interpretation - via actual content and/or markup

To answer one objection: I am aware that we discourage the use of
textual graphics. This discussion has no real bearing on that except
to note that in an ideal world where CSS were implemented and there
were strong associations between images and description/interpretation,
there would be no further use for the alt attribute as I have proposed
its use here.

Thoughts? Is this merely proof I've been up too late at night and my
mind isn't working properly, or is it a stroke of genius, or somewhere
in between?

--Kynn

PS:  The term 'longdesc' is dangerous to accessibility. This term
      should simply be 'description' or 'desc' and future versions
      of XHTML should drop the 'long' prefix. The name of the
      attribute supports the mistaken notion that alt text is for
      description -- what is longdesc a longer description than?
      Another suggestion to pass along to HTML WG.

CC: Courtesy carbon copy to Charles Munat, since I'm not sure if he's
     on the WCAG working group.
-- 
Kynn Bartlett <kynn@idyllmtn.com>                 http://kynn.com
Chief Technologist, Idyll Mountain            http://idyllmtn.com
Web Accessibility Expert-for-hire          http://kynn.com/resume
January Web Accessibility eCourse           http://kynn.com/+d201
Forthcoming: Teach Yourself CSS in 24 Hours
Received on Saturday, 2 February 2002 04:31:16 GMT

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