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How to describe Flowcharts, Schematics, etc

From: Leonard R. Kasday <kasday@acm.org>
Date: Wed, 11 Aug 1999 10:54:29 -0400
Message-Id: <>
To: w3c-wai-ig@w3.org
Most image on the web are decoration or icons with simple meanings like
"next page".  so ALT text and long descriptions are relatively

But some images convey information.  For example,

A simple linear sequence, like a flow chart with input going through a
series of processing stages to result in an output. 

A tree diagram, like a  company's organization chart.  

A more general diagram showing a bunch of interconnected objects, e.g. a
schematic diagram or an electronic circuit.

The most complex is a 3D machine, in motion if you want to make it even

Are there any guidelines on how to describe these diagrams?  

For example, you could use lists and nested lists for linear sequences and
trees respectively.  Or you could use prose.  More general diagrams are,
well, a more general problem.   What techniques are best for what purposes
and audiences?  What's good wording, especially for prose decriptions?

I'm mainly thinking of speech output here, since that's what most blind
surfers will be using, rather than Braille or tactile graphics.

This is no doubt hard to encapsulate... at some point you just have to get
a skilled technical writer, especially for the prose versions...

Leonard R. Kasday, Ph.D.
Universal Design Engineer, Institute on Disabilities/UAP, and
Adjunct Professor, Electrical Engineering
Temple University

Ritter Hall Annex, Room 423, Philadelphia, PA 19122
(215) 204-2247 (voice)
(800) 750-7428 (TTY)
Received on Wednesday, 11 August 1999 10:51:44 UTC

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