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RE: Example: Real-time feed of satellite photos

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Wed, 5 May 2004 12:59:06 -0500
To: "'WAI WCAG List'" <w3c-wai-gl@w3.org>
Message-ID: <auto-000027617630@spamarrest.com>
I think we are all on the same page.

Now we need to figure out how to word this such that the person doesn't need
to go to a non-normative doc to figure out if they passed.

 

Yvette's latest draft:

<suggestion>

For non-text content, provide text alternatives. Whenever possible the text
alternative should be equivalent to the non-text content, meaning it serves
the same function or conveys the same information as the non-text content.
If a text equivalent is not possible due to the nature of the non-text
content (for example: music and visual art), provide a text label or a
description.

</suggestion>

 

 is closer but still doesn't define "not possible due to nature of non-text
content" enough.  One can see people defining that in all sorts of way
including.  It is visual in nature.   It is meant for regular education
students.   It is scientific in nature.  Etc. 

 

what is it that makes these different.  That makes them indescribable?  

 

Or do we say, where the content can be described in X words or less?

Is this really what divides what should be described from what shouldn't?

 

Or do we just say, provide at least an X word description unless the
function or content can be described in less? 

 

Thoughts? 

 

 
Gregg

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

  _____  

From: John M Slatin [mailto:john_slatin@austin.utexas.edu] 
Sent: Wednesday, May 05, 2004 11:13 AM
To: Gregg Vanderheiden; WAI WCAG List
Subject: RE: Example: Real-time feed of satellite photos

 

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 13:59:36 GMT

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