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RE: Example: Real-time feed of satellite photos

From: John M Slatin <john_slatin@austin.utexas.edu>
Date: Wed, 5 May 2004 11:13:21 -0500
Message-ID: <C46A1118E0262B47BD5C202DA2490D1A1E3132@MAIL02.austin.utexas.edu>
To: "Gregg Vanderheiden" <gv@trace.wisc.edu>, "WAI WCAG List" <w3c-wai-gl@w3.org>
Gregg,
 
I agree that the example we've been discussing-- a real-time feed of
satellite photos, in this case of Texas-- aren't really intended to
create a "specific sensory experience" as per the wording of 1.1.  As I
noted, the solution Yvette proposed was to treat such content *as if* it
fit that description-- she didn't say that it *does* fit the
description, and I didn't say that either.  
 
I also agree that we can't set standards just by presenting examples,
and shouldn't have suggested it.  I also suggested that we might need to
add additional language to 1.1 and/or address this type of content under
1.2 (another scary thought).
 
To clarify further, I didn't really mean to propose that a "text
description" should be provided.  I was really thinking in terms of a
"text label."  The label might say, for example, "Satellite photo of
Harris County, Texas: 2004-05-05 10:23:34 CDT" or something like that--
it would probably include information identifying specific parts of
Harris County if the user had requested a more detailed view.  
 
Providing such a text label is feasible because the necessary
information is already available in the data stream-- otherwise it would
be impossible to let users specify the parameters of what they want to
see.  So my suggestion was that the script that collects user input and
finds the image that matches what the user wants could be modified to
(a) write the image to a new HTML page, and (b) write the existing text
information to an alt attribute or to the screen (if the text is written
to the screen, the script would set alt="").
 
John

"Good design is accessible design." 
Please note our new name and URL!
John Slatin, Ph.D.
Director, Accessibility Institute
University of Texas at Austin
FAC 248C
1 University Station G9600
Austin, TX 78712
ph 512-495-4288, f 512-495-4524
email jslatin@mail.utexas.edu
web http://www.utexas.edu/research/accessibility/
<http://www.utexas.edu/research/accessibility/> 


 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On
Behalf Of Gregg Vanderheiden
Sent: Wednesday, May 05, 2004 10:02 am
To: 'WAI WCAG List'
Subject: RE: Example: Real-time feed of satellite photos



This is an interesting approach for this example.  But I think I see
some problems.   And we would need to find out how to do this with
specification.  We can't have specification by example. 

 

I don't think this one actually is a sensory experience.   It is the
presentation of specific information.   The "big blue marble" picture of
the earth may be-but not these.   They just fall in the category of hard
to describe in a reasonable number of words.   (someone want to poke
their head up into live fire and suggest what 'reasonable number of
words" would be?)   Hence the problem.

 

This also doesn't deal with the issue of aggregated content in general. 

 

But we need to figure out a way to describe this or people could claim
that other images are just sensory experiences too.   It is  a slippery
slope


Gregg

 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 

  _____  

From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On
Behalf Of John M Slatin
Sent: Wednesday, May 05, 2004 9:29 AM
To: Gregg Vanderheiden; WAI WCAG List
Subject: RE: Example: Real-time feed of satellite photos

 

Actually, I think the approach Yvette suggested yesterday would work
better than just declaring such pages to be beyond the scope of
conformance.

 

Yvette suggested that such images-- real-time feeds of satellite
imagery-- could be treated *as if* they were content whose purpose is to
create a specific sensory experience (i.e., like music or painting): the
requirement would be to provide a brief text label or description.

 

That text label or description could be built automatically by a script,
using the identifying information that accompanies the image in the
satellite feed.  The text label could be coded as an alt attribute, or
the alt attribute could be null (alt="") and the identifying text could
be written to the screen of an HTML page which would be used to display
the image.  (It would be necessary to place the image on a page in order
to provide the text label; this would have the added benefit of allowing
a meaningful <title> element for the page as well).

 

We may want to consider adding a phrase about real-time feeds to 1.1, or
we may just want to handle this through examples.  (This one might make
a good example because it involves several technologies and their
techniques: XHTML and scripting at the very least, with no room for
direct human intervention to write alt text, etc.)

 

Or maybe this one really belongs under 1.2?

 

 

-- On a more theoretical (or at least more abstract) note, isn't there a
sense in which most Web content is aggregated content?  It's been true
for years now that Web pages may include content that resides at
multiple URIs on multiple machines.  It's the magic of the rendering
agent that makes it all appear to be on the same page.  (I'm thinking
even of very simple pages where text from one file is combined with
images in other files on other servers that may be halfway around the
world.)

 

This has been part of the concept of hypertext from the very beginning:
Ted Nelson called it "transclusion" back in the '80s, and I believe
there was a similar notion in Engelbart's NLS/Augment system back in the
'70s.

 

John

 

 


"Good design is accessible design." 
Please note our new name and URL!
John Slatin, Ph.D.
Director, Accessibility Institute
University of Texas at Austin
FAC 248C
1 University Station G9600
Austin, TX 78712
ph 512-495-4288, f 512-495-4524
email jslatin@mail.utexas.edu
web http://www.utexas.edu/research/accessibility/
<http://www.utexas.edu/research/accessibility/> 

 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On
Behalf Of Gregg Vanderheiden
Sent: Wednesday, May 05, 2004 8:58 am
To: 'WAI WCAG List'
Subject: RE: Example: Real-time feed of satellite photos

I think the answer comes from our 'scoping' approach which allows you to
specify which parts of your site conform at what levels. (see decision
from about 3 weeks ago).

 

Regulators may want to specify that specific parts of a site or specific
types of content conform to level but our current approach is that our
guidelines do not.    

 

We may later have a doc which makes suggestions on issues like this -
but we do not currently have this as part of our guidelines per recent
discussions and decisions. 

 


Gregg

 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 

  _____  

From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On
Behalf Of Donald F. Evans
Sent: Wednesday, May 05, 2004 8:34 AM
To: WAI WCAG List
Subject: Re: Example: Real-time feed of satellite photos

 

This is similar to the problem I face at AOL.  How does a content
aggregator conform to these standards?



John M Slatin wrote on 5/3/2004, 11:41 AM: 

	I received the following inquiry from someone who works at a
state agency here in Texas.  It presents an interesting challenge, and
it seems like something that might furnish a good example for us. I'm
also curious to know what solutions members of WCAG WG would propose in
order to meet WCAG 2.0.

	 

	<begin query>

	Our agency receives satellite photographs of Texas that are
automatically formatted into jpegs and loaded to our Web site. These
images are real-time, from one-hour to about 12-hours old. These are
continually and automatically updated on the site.

	I have an opportunity to review these Web pages now because they
are being revised to add additional types of satellite photos. It's my
job to make recommendations regarding the content's usability and
whether it meets state Web site accessibility standards. 

	On these pages, the user selects up to four different parameters
(using drop down lists) and then clicks a "display image" button. A jpeg
is returned to them in their browser. 

	Since these images are automatically updated, alt text specific
to each photo can not be added. And I'm not really sure how they could
be descriptive enough, anyway. Besides, the photos are not presented
inside Web pages, they are just the jpeg files.

	The state rule says we should provide an alternative format for
pages that are not accessible. I don't think that is possible in this
case. Would you suggest some disclaimer text on the page stating that
these images are not accessible?

	</end query>

	 

	Thanks!

	John

	
	"Good design is accessible design." 
	Please note our new name and URL!
	John Slatin, Ph.D.
	Director, Accessibility Institute
	University of Texas at Austin
	FAC 248C
	1 University Station G9600
	Austin, TX 78712
	ph 512-495-4288, f 512-495-4524
	email jslatin@mail.utexas.edu
	web http://www.utexas.edu/research/accessibility/
<http://www.utexas.edu/research/accessibility/> 

	 

	 
Received on Wednesday, 5 May 2004 12:14:06 GMT

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