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Re: Maps that are accessible

From: David Woolley <david@djwhome.demon.co.uk>
Date: Thu, 10 Jun 2004 22:08:16 +0100 (BST)
Message-Id: <200406102108.i5AL8GE05309@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org

> trained.  Tactile renderings are also quite expensive to produce if they are

And the static ones I have seen of maps (in railway stations, of the
station layout) have had very little richness of information compared with
a single page in a street atlas.

> Back from my digression though, the list would work if enough though were

Lists don't tell you about what surrounds the item in the list. 

> put into it no matter how long it was.  I know that scrolling may not be the

1) thought costs money - street map servers exist because the images of
   the maps already exist and therefore the cost of providing the maps 
   basically just has to exceed the lost sales revenue from the book versions
   of the maps - a map server can therefore be operated with relatively 
   little clerical effort (actually most servers do index by street name,
   so there is quite a bit of clerical input - but that effort has gone
   in after money has been made from limited coverage);

2) any commercial map server mustn't allow the user to capture the underlying
   topological information, because the market price for that is much much
   higher than for the printed map, and, for the UK at least, even maps
   prepared by the government (Ordnance Survey) are expected to make
   revenue, and that was the case even before partial privatisation.

> best answer but there are additional navigational approchases that can be
> taken.  Take a look at the browse shelf of:
> http://www.audiobooks.com

Doesn't sound like the 2 dimensional structure in a geographical map.

> of course, you have to know what lies between two points along the
> alphabetic scheme, but it works quite well.  I've seen nothing visual that
> if dealt with properly cannot be handled intellectually by a person who is
> propperly equipped intellectually and other wise to handle it.  In some

Forming the mental image is not the problem.  The real problem is that 
maps are extremely high bandwidth communication devices for visual-spatial
information and efficiently use the opposite side of the brain from
that used by sequential language.  Most images on the web have very little
real information content, often no more than that in the text of which they
are images, or may even have disinformation content; a small amount
of text can substitute for most of what is important, for the user,
in them (although it probably cannot substitute for their value to the
content provider).  Maps are the one exception.

Tactile maps don't provide the level of parallelism in input to the brain
that can be achieved by visual maps, and speech certainly doesn't.  To
get anything like the full information from a map over a speech interface,
you would require an extremely interactive interface, with a certain
degree of telpathy, so that it knows which features are of interest, 
even if they not, and a certain amount of AI, so that it knows that 
particular patterns of building have particular significances (e.g. one
pattern indicates very rich neigbourhoods and another pattern indicates
hospitals, but neither of these facts will actually be printed on the

The second part of the problem is that maps can be processed very efficiently
by the eye and brain, but are very difficult to process, in image form,
by a machine.  That gives a digital rights management advantage, in that
providing the image of the map doesn't provide the underlying data in a
machine processable form.  It's a bit like the problem of images used to
distinguish humans from machines accessing a site.  UK maps are provided as
bitmaps, German ones are provided in vector format, but only through a
downloaded Flash or Java interface.
Received on Thursday, 10 June 2004 17:39:39 UTC

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