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Perceivable.

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Thu, 25 Apr 2002 21:26:32 -0500
To: <w3c-wai-gl@w3.org>
Message-ID: <00b401c1ecc9$c8a7db30$81346880@laptop600>
 

 

See below marked GV:  

 

 

Current wording

Perceivable. Ensure that all content can be presented in form(s) that
can be perceived by any user - except those aspects of the content that
cannot be expressed in words. 

 

 

[js: 

The more I read and think about this, the more uncomfortable I get.
What are the "aspects that cannot be expressed in words"?  I assume that
the intent of this exception is to exclude such things as musical notes,
the brushstrokes in a painting? In other words, that we don't want to
seem to be demanding that Web developers find some way to allow people
who are Deaf to have a direct perception of audio content, or enable
people who are blind to have direct visual perception of images, fonts,
etc.  If this is correct, I think we should somehow make it explicit.
But we should be mindful that we're asking Web developers to make some
very subtle philosophical and aesthetic distinctions, identifying what's
irreducibly non-verbal.  Do we really want to do that?

 

GV:  I can't think of how to make it explicit without losing its general
nature. (and that would narrow its meaning).   

 

Would it change the intent of this provision to rephrase it as follows:
"

 

"Perceptible. Ensure that any Web content that can be expressed in words
(language?) can be perceived by any user, either directly or with the
aid of assistive technology.  Provide equivalent alternatives for
content that cannot be perceived by all users, either directly or with
the aid of assistive technology."?

 

GV:  I think perceivable is better than perceptible.   Not sure why.

 

I think the 'expressed in words" as an escape clause - is easier to
understand than as an entry clause.  Also I think the principle is
easier to understand in its simple form - with the escape clause
following.

 

(I do think it sound awkward though. Its just that the smooth versions -
are harder to understand until after you understand it.)  

 

 

Try it on some friends.

 

(End of this GV block)

 

 

I am not convinced that we really need the wording about content that
"cannot be expressed in words" if we make it clear that making
non-verbal content available via assistive technologies satisfies this
guideline.  I worry that the presence of the phrase about content that
cannot be expressed in words will create a huge obstacle/firestorm that
could threaten adoption of WCAG 2.0]

 

GV: "Making content available via assistive technology" has no meaning
to most web designers - and that isn't what they have to do.  Better to
express this in terms that they can relate to, don't you think?

 

Tough one to get your arms around - isn't it.  

 

Gregg

 

 

-- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Human Factors 
Depts of Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 
Gv@trace.wisc.edu <mailto:Gv@trace.wisc.edu>, <http://trace.wisc.edu/> 
FAX 608/262-8848  
For a list of our listserves send "lists" to listproc@trace.wisc.edu
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Received on Thursday, 25 April 2002 22:27:28 GMT

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