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Re: Updating 2.4, re-revised

From: Wendy A Chisholm <wendy@w3.org>
Date: Thu, 31 May 2001 15:36:38 -0400
Message-Id: <>
To: Adam Victor Reed <areed2@calstatela.edu>, gv@trace.wisc.edu, <w3c-wai-gl@w3.org>
My conclusion, after reading all the messages in this thread, is to leave 
2.4 as it was since we are giving user's control of how long they need to 
interact with the content.  It is not feasible to say don't limit the time 
at all.

Gregg, Adam included flicker in his proposal since it is in the current 
WCAG draft under checkpoint 2.4.

in the 20 January 2001 draft it says, "2.4 Give users control over how long 
they can spend reading or interacting with content.  Mechanisms that 
required a timed response include:  automatic 
refresh,  redirection,  flicker,  blinking  This can be satisfied by 
providing an option to deactivate automatic updating, or to control the 
rate at which it occurs. User agents may also offer control over this 
effect. Note that flicker effects can cause seizures in people with 
photoepilepsy.  "


At 01:21 PM 5/31/01 , Charles McCathieNevile wrote:
>I have a slightly different approach I think, or maybe I just think about it
>in different words.
>To make the thing accessible to various groups of people you need to have the
>option to stop the timeout. There are some cases where this is genuinely not
>feasible, and those things are not going to be accessible to such people. In
>a context such as the Disability Discrimination Act in Australia, any
>complaint is likely to result in a finding that the site cannot be made
>accessible for some external reason, and therefore is eligible for an
>exemption (like undue burden provisions in other situations). That doesn't
>mean they are accessible, it means that they are not, and cannot be, and it
>is not their fault.
>This, by the way, is the basis for having a more granular conformance profile
>as well as the nice simple scale of A, double-A, triple-A. Such a site may
>pose no problems to certain groups of people, and it would be useful to have
>a mechanism for stating that explicitly. EARL provides just such a mechanism.
>But for the most part, it is better to aim for accessibility to all, at some
>level, and the current scheme provides a reasonably simple approach to
>dealing with that.
>On Thu, 31 May 2001, Matt May wrote:
>   ----- Original Message -----
>   From: "Adam Victor Reed" <areed2@calstatela.edu>
>   > And it is not difficult to design bypass
>   > technologies that will still meet legitimate security and economic
>   > constraints.
>   I disagree. Timeouts such as those present in Dell's site (along with those
>   at my former companies) are based on hard business rules on the back end.
>   Expedia needs you to lock in your reservation so it can relay that request
>   to the computerized reservation system it gets its data from. (And it uses
>   meta refreshes to keep the HTTP connection alive while it contacts the slow
>   pathetic creature.) HomeGrocer and Webvan needed to accurately manage
>   delivery trucks and merchandise in the best possible manner. Resource
>   management is critical in e-commerce.

wendy a chisholm
world wide web consortium
web accessibility initiative
seattle, wa usa
tel: +1 206.706.5263
Received on Thursday, 31 May 2001 15:30:47 UTC

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