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Re: How to describe Flowcharts, Schematics, etc

From: Charles McCathieNevile <charles@w3.org>
Date: Thu, 19 Aug 1999 15:05:00 -0400 (EDT)
To: Steven McCaffrey <smccaffr@MAIL.NYSED.GOV>
cc: CHRIS.KREUSSLING@ny.frb.org, dave.pawson@virgin.net, w3c-wai-ig@w3.org
Message-ID: <Pine.LNX.4.10.9908191456560.6582-100000@tux.w3.org>

The ability to traverse a hyperlinked document (or set of documents - the
boundary lines are pretty arbitrary) is precisely the ability to go over
those relationships again and again. There are two ways of doing this - one
is by starting from a point, and jumping around, and the other is by finding
a named element and knowing what it has relationships with. The other piece
of information that is important is what kind of relationships they are - in
the HTML/XML world there are a couple of predefined relationships based on a
particular structure - the tree structure which defines parent, child and
sibling relationships, and in HTML there is also a link between two anchored
points. In the HTML linking mechanism there is a rel and a rev attribute
which can be used to define arbitrary types of relationship - for example
that one end of  the link is a stylesheet for the other, or that one end of a
link is the next document in a sequence.

To express a tree in SVG is probably a pretty easy exercise. To add links
among points in the tree, and have it look reasonable, is perhaps more
difficult. But it seems to be well within the bounds of the possible.


On Thu, 19 Aug 1999, Steven McCaffrey wrote:

  Hi Dave, Karl, Len, Charles etal:
  "...(say) a hyperlinked HTML version
  for the VI members of the group,..."
  What is this version like?  If a blind person tabbed from link to link, what would be spoken by a screen reader (i.e. what is the linked text?)
  A static HTML version  would be o.k. for input to a more interactive program but not sufficient for output for blind 
  users to gain equivalent access to the underlying information structure.  A good exercise is to try to comprehend a chart/diagram you have not seen before by having it described to you (i.e read aloud) by a friend/colleague, without, of course, looking at it yourself.  The words (labels of nodes) and relational information (e.g. (abstract tree data structure terminology)"is a child of  or (more concretely) for an organizational chart  "works for") goes past your ears.  Visual information allows the viewer to refresh his/her memory simply by focusing her/his eyes on any deisired portion of the picture.  To gain the same flexibility, you would have to ask your friend/colleague, or computer, to read something of interest, at the desired level of detail, again. Thus the need for interactivity.
Received on Thursday, 19 August 1999 15:05:55 UTC

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