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FW: 506 definition of structure

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Fri, 4 Jun 2004 08:58:07 -0500
To: <w3c-wai-gl@w3.org>
Message-ID: <auto-000057426353@spamarrest.com>
 Sorry John


Let me put it this way.


We say that authors must      separate information and structure from


If structure is information then   that is kind of like saying        women
and people.   


See my problem? 




PS very interesting discourse below. 




From: John M Slatin [mailto:john_slatin@austin.utexas.edu] 
Sent: Friday, June 04, 2004 8:26 AM
To: Gregg Vanderheiden
Subject: RE: 506 definition of structure


Gregg asks: "If text is structure what is information?"


John responds: It depends (what did you think I'd say? <grin>) And it
depends in part on what level of abstraction you're talking about.


What humans perceive as "information" doesn't exist in the abstract: it is
embodied in some form, some medium. Information may exist in the form of
text; it may exist in the form of graphics; it may be embodied in a
mathetmatical equation, a chemical formula, an animation generated by a
simulation, a video, etc. If a given human already knows the material in
question, she or he doesn't perceive it as information, though it may count
as information to the person sitting at the next desk. Information *has*
structure, and structure is information.  In our context, the markup that
create structure is information about the shape of the information that a
given document makes available.



Gregory Bateson says information is news of difference that makes a
difference.  From this standpoint, a chameleon is always trying *not* to
become information-- it wants (biologically speaking) to be
indistinguishable from surrounding context.  If the context changes faster
than the chameleon's skin can respond, it becomes information, and instantly
vulnerable to predators to whom the difference makes a difference.


The self-organizing behavior of complex adaptive systems (like humans or the
Web) depends on a given system's ability to convert what information theory
would call "noise" (meaningless stuff coming in from outside) into
information *about the system itself*; the system then uses that information
to reorganize itself at a higher level of complexity.  The Web was exactly
such a phenomenon to the whole IT industry, and new technologies for
producing and rendering Web content force the same kinds of reorganization--
hence our current effort to rewrite the accessibility guidelines at a higher
level of complexity that takes account of all the technologies that are now
used to produce Web content.  Our guidelines will beomce another rock in the
pond, etc, etc.


But the proposed definition doesn't say "text *is* structure."  It says that
text is one of the types of material that may be included in a Web resource.
As far as I know, though, for all Web resources that have source documents
that employ markup languages (HTML, XML, SVG, etc.), it might be literally
correct to say "Text is structure" because everything in the source document
*is* text.  And if you go farther down the ladder of abstraction even
complex graphics and multimedia materials that are merely *referred* to in
the source document reduce to strings of ones and zeroes, which can be
represented in textual form.  So it's text all the way down, or almost all
the way down.



"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/>


-----Original Message-----
From: Gregg Vanderheiden [mailto:gv@trace.wisc.edu] 
Sent: Friday, June 04, 2004 12:05 am
To: John M Slatin
Subject: RE: 506 definition of structure



John?  If text is structure  what is information?






From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of John M Slatin
Sent: Wednesday, June 02, 2004 10:15 AM
To: w3c-wai-gl@w3.org
Subject: 506 definition of structure


At the 27 May telecon, Jason and I took an action item to work on the
definition of structure.  The definition appears below.  Note: it is common
practice for dictionary definitions to include examples that illustrate how
the term is used in practice.  In this spirit, the proposed definition
refers to specific technologies (HTML, SVG, and MathML) that make it
possible to indicate structural aspects of different kinds of content. We
believe that it's clear from context that using these examples does not
create an implicit requirement that SVG is the required format for all
graphics or that MathML is the required format for mathematical expressions.


Additional note: one of our goals was to bring this definition into
alignment with our commitment to plain language. The definition as a whole
receives a Flesch Reading Ease measure of 42.4 and a Flesh-Kinkaid Grade
Level of 10.0 (which corresponds to the beginning of the second year of high
school in the US). This is actually at the high end of the scale-- according
to Canada's Northwest Literacy  Council, a grade level of 10+ is appropriate
if the document contains specialized technical information and the audience
is familiar with the topic and has good literacy skills.  However, the same
group recommends a grade level of 7-9 for material intended for the general
public that contains new terms and concepts or specialized subject matter.
(Northwest Territories Literacy Council. A plain language audit tool.
Available at http://www.nwt.literacy.ca/plainlng/auditool/cover.htm. The
specific material about readability is at


<proposed definition>


Structure includes all the parts of a Web resource and the way they are


The parts of a Web resource may include text, graphics, mathematical
equations, multimedia, etc. Some parts may contain other parts or create
relationships between two or more parts.     


Some relationships are hierarchical. Examples include sections and
sub-sections of HTML documents, where each section or sub-section begins
with a title that is marked as an HTML heading.  The material in each
section is logically related to the heading. The headings show the logical
organization of the document.


Some relationships are not hierarchical. Examples include links between two
parts of the same document or between two documents. 


Mathematical expressions also have structure.  It is possible to show this
structure.  For example, MathML can show the order in which calculations
should be performed.    


Graphics may also have structure. Examples include flowcharts, diagrams,
maps, and other complex images. SVG makes it possible to identify the
structure of graphics.


User agents may make the structure of Web resources evident to the user.


</proposed definition>

"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/>


Received on Friday, 4 June 2004 09:58:52 UTC

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