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Re: Some concrete suggestions Re: Cognitive issues (was Re: woodcutter)

From: Marja-Riitta Koivunen <marja@w3.org>
Date: Thu, 06 Apr 2000 20:20:33 -0400
Message-Id: <>
To: Charles McCathieNevile <charles@w3.org>, Jason White <jasonw@ariel.ucs.unimelb.edu.au>
Cc: Web Content Accessibility Guidelines <w3c-wai-gl@w3.org>
It seems that we have at least 3 approaches that can all be explored at the
same time and that can support each other when we gather the results
together. 1) Learn about the various groups of CD users, 2) learn about the
problems that individual CD users have and create sample scenarios for
them, 3) think about what makes the use of web easy in general as even if
that is not always enough that probably also helps CD users.

Charles's suggestions go to the last category and I tried to brainstorm
couple of more very drafty visual guidelines from this point of view with
no connection to any disabilities yet but for general usability:

GL: Think carefully what are the main points you want to communicate.
Provide images and diagrams highlighting the main points in your
presentation. It is good practice if users can get an idea of the content
by browsing through the images.

GL: Try to simplify complicated explanations by providing examples and
outlines that help the users to see the structure as a whole before going
into details. Support the explanation with images and do simplify them too
so that the message is clear.

GL: Provide visual diagrams of data that help to understand the context and
compare and relate the data. Provide visual outlines of architectures or
other structures.

GL: Use several graphical means to relate visual object (- this is actually
don't use color alone GL) e.g. gestalt rules. Actually we never mentioned
interaction of colors in the GL = a little patch of color surrounded by
other color can look totally different when the surrounding color changes.

GL: Try to disambiguate the images so that there are no hidden pictures
e.g. some see white object on black and others black object on white. No
not use black stripes or color that interfere e.g. all the psychological
stuff that you see in textbooks.

GL: When you want to communicate a difference make it clear in the image.
E.g. not lines that are almost the same lenght but clearly have a clear
difference in lenght.



At 05:13 AM 4/3/00 -0400, Charles McCathieNevile wrote:
>These are just-poured with very wet concrete, so can be changed quite a lot
>before it cures.
>Illustrate text content with appropriate graphics or multimedia.
>Some things can clearly be illustrated to make them more accessible. Examples
>abound in textbooks (quantum physics, electrochemistry, architecture,
>construction of all kinds, road rules and navigation techniques) Flow charts
>and structure diagrams can be used to illustrate complex ideas and
>For people who have difficulty reading, this sort of illustration can greatly
>improve their understanding of or ability to use Web content. For people who
>are unable to read without extreme difficulty, this can make the difference
>between having an idea what something is about and using whatever techniques
>are available to understand the content (including reading software, finding
>related material through metadata-based retrieval, or further study of the
>available content), or not being able to understand what sort of concepts are
>being presented.
>Some techniques:
>  Use sound. 
>    Although this will not work for everyone (any more than a longdesc is
>    helpful to anyone) there are some kinds of content that can be easily
>    illustrated with sound. The emergence of markup languages for voices
>    and music will make it easier to do this in an accessible manner.
>  Use clearly drawn graphics with good contrast. 
>  Use internationally or widely recognised symbols, with appropriate colours
>    There are many symbols which are widely recognised when used in an
>    appropriate context. Traffic symbols, those used in airports and hotels,
>    and more specialised symbols such as those in flowcharts and circuit
>    diagrams can all help clarify meaning for an audience that understands
>    the content matter but has difficulty with the text.
>  Use photographic images for specific references, drawings or symbols for
>  general references
>    Where a piece of content is about a specific person, it is appropriate to
>    use an image of that person. Where a piece of content is about cars in
>    general it may be more appropriate to use a stylised or generic drawing
>    of a car
>  Use layouts that reflect the structure of the content
>    One of the reasons for including structure is so that it can be
>    represented in many media. Most visual readers are used to deriving
>    semantics from presentation conventions that are not fixed, but are
>    nonetheless describable - things that are larger or decorated are likely
>    to be headings, layout that has a hanging indent (where this is not the
>    norm) or bullets or numbers is likely to be some kind of list, and what
>    is indented is likely to be especially or only relevant to the initial
>    line or items in it, etc.
>  When user agents or appropriate language provide the ability to control
>  animation, use it to demonstrate complex motions
>My knowledge of graphic communication is limited - I am sure we can find
>better and refine this. Likewise with sound and animation. 
>Charles McCN
>Charles McCathieNevile    mailto:charles@w3.org    phone: +61 (0) 409 134 136
>W3C Web Accessibility Initiative                      http://www.w3.org/WAI
>Location: I-cubed, 110 Victoria Street, Carlton VIC 3053
>Postal: GPO Box 2476V, Melbourne 3001,  Australia 
Received on Thursday, 6 April 2000 20:27:23 UTC

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