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Re: How to describe Flowcharts, Schematics, etc

From: Chris Kreussling <CHRIS.KREUSSLING@ny.frb.org>
Date: Tue, 17 Aug 1999 10:55:44 -0400
To: w3c-wai-ig@w3.org
Message-id: <s7b94061.005@ny.frb.org>
I've had a chance to read others' responses over the past week. One of my favorite sayings (I don't know who said/wrote it): "The map is not the territory." In the context of this discussion, the diagram is not the model. We need to convey the content and structure of models - organization charts, schematics, etc - independent of their appropriate presentation for a particular user, or the available representation.

The Object Management Group <www.omg.org> has done a lot of work in this area. In particular, I think their Meta-Object Facility (MOF) and XML Metadata Interchange (XMI) may be applicable. 

MOF is a Meta-Meta-Modelling Language: a syntax and semantics for describing other meta-models: org charts, schematics, computer systems, whatever. XMI is an XML format for exporting and importing arbitrary meta-models to and from MOF. Through XMI, any meta-modeling language could be converted into any other meta-modeling language. 

*In theory* any model could be converted into XMI for storage on a server and transmission over the Web, e-mail, whatever. A User Agent can parse the XMI to read the model and present it to the user. To present a different class or set of models, you develop a meta-model, XML DTD, and XMI transforms. Optionally, you develop stylesheets for different presentation media.

For more information about XMI see <http://www.software.ibm.com/ad/standards/xmi.html> or <http://www.omg.org/news/pr99.html#xmi>.

<author>Chris Kreussling</author>
<disclaimer>The views expressed are 
those of the author and do not necessarily 
reflect the position of the Federal Reserve 
Bank of New York or the Federal Reserve 

>>> <w3c-wai-ig@w3.org> 08/11 10:51 AM >>>
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 Tuesday, 17 August 1999 11:02:26 UTC

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