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Re: HTML Action Item 54 - ...draft text for HTML 5 spec to require producers/authors to include @alt on img elements.

From: James Graham <jg307@cam.ac.uk>
Date: Wed, 21 May 2008 23:26:21 +0100
Message-ID: <4834A18D.1000708@cam.ac.uk>
To: Steven Faulkner <faulkner.steve@gmail.com>
CC: Ian Hickson <ian@hixie.ch>, public-html@w3.org, W3C WAI-XTECH <wai-xtech@w3.org>, wai-liaison@w3.org

Steven Faulkner wrote:
> hi Jgraham
>> That would appear to preclude requirements such as:
>> "The alt attribute [...] must contain a text alternative that serves the equivalent purpose as the image. What is to be considered an equivalent purpose, depends on the way an image is used."[1]
> 
> well, no, there are methods for deciding the appropriateness of  text
> alternatives according to the context the image is used in. These are
> described in WCAG 2.0 for example.

Do you mean [1] or something else? All the information in that document 
assumes that the assessor knows the purpose of the image; that is to say 
the author's intent. Sure, in many cases it would be possible to guess 
the author's intent from the page* but that is also true for many of the 
other conformance requirements that require knowing the author's intent. 
Indeed, it is often possible to guess whether it was practical for the 
author to provide alt text or not depending on the nature of the image, 
how it was uploaded, how many other images were uploaded, and so on. 
Nevertheless only the author can be considered an authoritative source 
for any of this information.

* Although it is possible to construct cases where it is not; consider a 
psychological test in which the user is asked to perform some task 
involving images but the experimenter is looking for some subconcious 
response not directly related to the task

[1] 
http://www.w3.org/TR/2008/WD-UNDERSTANDING-WCAG20-20080430/text-equiv-all.html

-- 
"Mixed up signals
Bullet train
People snuffed out in the brutal rain"
--Conner Oberst
Received on Wednesday, 21 May 2008 22:29:40 GMT

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