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BIG ISSUE -- re Delivery Units

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Wed, 8 Feb 2006 15:23:45 -0600
To: <w3c-wai-gl@w3.org>
Message-ID: <00d601c62cf5$f1b52cb0$ee8cfea9@NC6000BAK>
Currently we have a number of success criteria that talk about delivery
units.    However, the delivery unit is anything you can get with an HTTP
request. 

(All of the sc that the term delivery unit is used in our guidelines are
listed at the bottom of this email.)

 

So a page with all of its images is a D U.  But each image by itself is also
a D U.  

 

The problem is 

 

1.	the images don't pass our guidelines
2.	if you make any kind of claim for your site (or any URI pattern) it
would include the URI's for the images etc (unless you stored the images off
in some remote location)

 

This is not what we intend.    After looking at this for awhile Ben and John
and I are suggesting that perhaps we focus on the delivery unit you get from
a user request and not the subsequent delivery units that are fetched as
part of it.   To do this we would need to define a new entity. 

 

John, Ben and I have discussed and examined this and are proposing a new
term "Web Unit" that would replace all occurrences of Delivery Unit in the
guidelines and related documents.

 

Take a look.  Think hard.  And then send your comments.  

 


Web Unit (e.g. Page)


    A collection of information, consisting of one or more resources,
intended to be rendered together, and identified by a single Uniform
Resource Identifier (URLs etc.).     

 

NOTE:    This term was adapted from the definition of web page in Device
Independent group and Web Characterization Terminology & Definitions Sheet
except concept of simultaneity was removed to allow the term to cover
interactive multimedia content.

 

Example 1:  A web page including all embedded images and media. 

 

Example 2:  An interactive movie like shopping environment where the user
navigates about and activates products to have them demonstrated, and moves
them to cart to buy them. 

 

 

Here are all the occurrences of Delivery Unit. 

 

2.2.2  [P/D] Content does not blink
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#blinksdef>  for more than 3
seconds, or a method is available to stop any blinking content in the
delivery unit
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef> . [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#time-limits-blink>  to meet 2.2.2] 

2.4.2 [P] More than one way is available to locate content within a set of
delivery <http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>
units where content is not the result of, or a step in, a process or task.
[How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-mult-loc>  to meet 2.4.2] 

2.4.3 [P] Blocks of content that are repeated on multiple perceivable units
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#perceivableunitdef>  [NEEDS
TO BE CHANGED TO DU]  are implemented so that they can be bypassed. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-skip>  to meet 2.4.3] 

2.4.4 [P] Delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  units have
titles. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-title>  to meet 2.4.4] 

2.4.5 [P] Each programmatic reference
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#programmatic-referencedef>
to another delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  unit or to
another location in the same delivery unit, is associated with text
describing the destination. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-refs>  to meet 2.4.5] 

2.4.7 [P] When a delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  unit is
navigated sequentially, elements receive focus in an order that follows
relationships and sequences in the content. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-focus>  to meet 2.4.7] 

2.4.8 [P] Information about the user's location within a set of delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  units is
available. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#navigation-mechanisms-location>  to meet 2.4.8] 

3.1.1 [P] The primary natural
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#natural-langdef>  language
or languages of the delivery unit can be programmatically determined
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#programmaticallydeterminedde
f> . [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#meaning-doc-lang-id>  to meet 3.1.1]

3.2.3 [P] Navigational mechanisms that are repeated on multiple delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  units
within a set of delivery units occur in the same
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#samerelorderdef>  relative
order each time they are repeated unless a change is initiated by the user.
[How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#consistent-behavior-consistent-locations>  to meet 3.2.3] 

3.2.4 [P] Components that have the same functionality
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#samefunctionalitydef>  in
multiple delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  units
within a set of delivery units are identified consistently. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#consistent-behavior-consistent-functionality>  to meet 3.2.4] 

4.1.1 [P/D] Delivery
<http://www.w3.org/WAI/GL/WCAG20/appendixA.html#deliveryunitdef>  units can
be parsed <http://www.w3.org/WAI/GL/WCAG20/appendixA.html#parsed-unambigdef>
unambiguously and the relationships in the resulting data structure are also
unambiguous. [How
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20060117/Overview.h
tml#ensure-compat-parses>  to meet 4.1.1]
<http://trace.wisc.edu/bugzilla_wcag/issuereports/navigation-mechanisms_issu
es.php> 

 
Received on Wednesday, 8 February 2006 21:23:56 GMT

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