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RE: Using content negotiation to serve content variants to people wit h special needs?

From: Jukka Korpela <jukka.korpela@tieke.fi>
Date: Thu, 20 Jun 2002 09:46:36 +0300
Message-ID: <621574AE86FAD3118D1D0000E22138A95BDD42@TIEKE1>
To: w3c-wai-ig@w3.org

David Woolley wrote:

> I think the problem with content negotiation is that it 
> requires server configuration.

That's certainly a problem, but I don't think it's the biggest problem.
Rather, users and user agents are the problem; most users have no idea of
language negotiation, so we can't expect their browsers to have language
preferences set to correspond to the actual preferences. This is of course a
chicken and egg problem: why bother configuring one's browsers when so few
sites make use of the preferences? (There are even concerns of privacy,
especially since if you use Netscape 4 to post to Usenet, the browser sends
your language preferences in the message headers!)

On the other hand, the trouble of setting up content negotiation so that,
for example, there's a selection between an English (en or eng) version and
an American sign language version (sgn-US), is typically much smaller than
the work needed to actually produce the two versions and put them onto the

If we think that content negotiation is a method that should be promoted,
for use when applicable, then probably the most important step would be to
make browsers _prompt_ for the user's preferences upon installation. It
would be a simple dialogue in most cases. Of course, this would be just part
of the interaction needed upon installation (or start of use), and things
like default font size and face selection are more important in practice.
People often say that 99 % of user's don't know how to change the browser
settings, or even that they _can_ be changed. This is not that far from
truth I suppose - though people with serious disabilities surely _need_ to
know such things, or have someone do them for them - but this just
emphasizes the need for actively prompting for the user's choices.

In the User Agent Accessibility Guidelines,
especially items 4, 5, and 11 emphasize the need for the _possibility_ of
user's control over the browser. But I think there's something to be added
there: to encourage the user to exercise control, even actively requesting
commands from the user. This is a difficult topic, since the installation
(or start of use) phase should be as simple as possibility, and it should
involve simple concepts and actions. There's little point in making the user
fine-tune the browser behavior in all the different ways that it could be
done. But I think that a question that asks the user specify the languages
that he knows, in order of preference, would be quite comprehensible to most

> Most informational page developers are one technology people,
> and if it can't be done with a meta element in HTML, it can't 
> be done at all

How very true - but that's one of the problems that need to be solved in
order to make people create more accessible pages.

> - - it can be difficult to have a satisfactory
> way of overriding the negotiated language (without 
> reconfiguring the browser.

Indeed, and that's one of the reasons why the different versions should have
explicit links to each other (or, if there are lots of versions, to a
version selection page, which would also be used as the "fallback" version
in negotiation, e.g. to be used to avoid the 406 Not Acceptable response,
with all the confusion and negative feelings that it causes).

> The only real life negotiated pages I have come across are 
> Windows Update and Google (W3C negotiates graphics formats).

Content negotiation isn't very common yet, and there are several issues to
consider, pros and cons, but I think it could be quite useful for special
applications, like delivering optimal versions to people with special needs.
The browser configuration could be done by someone else, by a person who
helps the user in different problems anyway.

Jukka Korpela, senior adviser
TIEKE Finnish Information Society Development Centre
Phone: +358 9 4763 0397 Fax: +358 9 4763 0399 
Received on Thursday, 20 June 2002 02:46:53 UTC

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