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Fwd: Re: Contrast and grayscale

From: Chuck Letourneau <cpl@starlingweb.com>
Date: Fri, 28 Jun 2002 09:47:39 -0400
Message-Id: <>
To: w3c-wai-eo@w3.org
I forgot to copy this reply to Jean-Marie to the EO list.  So, here you go...

>Date: Mon, 24 Jun 2002 22:40:09 -0400
>To: "Jean-Marie D'Amour" <jmdamour@videotron.ca>
>From: Chuck Letourneau <cpl@starlingweb.com>
>Subject: Re: Contrast and grayscale
>Jean-Marie, you raise a good point relating to the metrics of usability 
>and accessibility.  Determinations of suitable contrast, minimum usable 
>size (e.g. of linked images) and clearness and simpleness of text are, for 
>most evaluators, going to be subjective.  Even if some application or tool 
>can analyze color content and contrast (see Eric Velleman's reply to 
>Jean-Marie), or active area size, or language complexity, and warn an 
>evaluator that there is a potential problem, there is no single fix that 
>will satisfy all people.  Because of the wide range of human functional 
>abilities it is very difficult (perhaps impossible) to specify lower 
>limits that will satisfy everyone.  The subjective techniques we propose 
>for assessing these things may be the best we can do: in some cases we 
>hope they will clearly identify potential problems to the evaluators -- in 
>other cases they may miss the mark entirely.
>I think we must continually remind designers that incremental or relative 
>improvements do have merit: if you improve contrast, choose better colors, 
>make text larger, make content clearer, etc. you will include more 
>people.  But in many cases, it may only be end users who can verify if any 
>design choices we make are sufficient. This is why  "User testing of 
>accessibility" and why having mechanisms for capturing (and procedures for 
>acting on) user feedback is such an important requirement for Conformance 
>Chuck Letourneau
>At 18/06/02 09:00 AM, Jean-Marie D'Amour wrote:
>>I have tested our recommandation about evaluating contrasts with 
>>grayscale in the context of a trainig.
>>I'm not satisfied about this because this kink of evaluation is very 
>>The checkpoint itself is rather subjective.
Received on Friday, 28 June 2002 09:48:29 UTC

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