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Re: Maps that are accessible

From: David Woolley <david@djwhome.demon.co.uk>
Date: Wed, 9 Jun 2004 21:47:58 +0100 (BST)
Message-Id: <200406092047.i59KlwH04880@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org

> 
> Dave, mouse keys don't work with screen readers and even their built in
> mouse key simulation doesn't work if there is no associated text.

Maps don't work with screen readers either, particularly UK maps which are
bitmapped.  The question was specifically about (geographical) maps.
You have to solve the problem of presenting maps, within commercial,
particularly intellectual property, constraints, before you need to worry
about pointing within them.

The only, to me, sensible way of handling a map with voice and keyboard
only, would be to download an applet and send the map as the topology
information, then use a user interface like the original text Adventure
programs.  To handle it server side, response time considerations would
suggest that one would need to switch to a telnet interface.  Sending the
raw topology, in a format processable by open tools, would probably be
impossible to license from the mapping data owners.

You can't do this with UK maps, as the street level maps, used on the web,
aren't available in anything but image form, and I suspect the large
scale maps, and vector street maps (as used in GPS devices), wouldn't
be licensable in vector form for free web access, although the data is
licensed for things like GPS car navigation systems.

Although the Adventure type interface is OK for giving a route from A
to B, to get the full benefit of a map, without sight, I think you would
need to use a two dimensional tactile interface, intended for diagrams,
and one would hope that any interactive such interface would have support
for pointing input.  I think it may be possible to get read only devices,
but difficult, or impossible, to find interactive devices.

MouseKey interfaces are not the right solution for discrete input
selection of links and pulldown lists, but they are appropriate for
pointing to parts of images where every different pixel position is
signifcant.    The only alternative to pointing, either directly, or by
manipulating a cursor, is to key in coordinates, which quite an abstract
concept, and arguably not terribly useful unless you can appreciate the
full two dimensional structure, which, as I see it, requires visual or
tactile interface devices.
Received on Wednesday, 9 June 2004 16:48:46 UTC

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