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Success criteria speak for themselves

From: Wayne Dick <waynedick@knowbility.org>
Date: Tue, 18 Feb 2014 12:09:58 -0800
Message-ID: <CAC9gL75D+4PPoPms+O5PpPqTeEV0rc8TRvQhSh7zumq0X5KxoA@mail.gmail.com>
To: w3c-wai-ig@w3.org
Hi Everyone ,

Below is from my presentation on Fri. March 21 at 8AM at the CSUN
Conference.  It challenges the current narrow interpretation of SC 1.3.1 by
the WCAG WG.  A few years back WCAG WG made the incorrect interpretation
that 1.3.1 did not apply to the text level semantics that conveyed
important relationships visually but not semantically.  Here is a counter
example to their interpretation.  The WCAG WG perhaps did not mean this
interpretation when they wrote the criterion, but that doesn't change its

 Example (HTML) --
 This example compares coding a relationship using a meaningful element
like <dfn> to define a term versus using the semantically void element
<span> with inline style to define the same term.   Consider the following
sentence: The hypotenuse of a right triangle is the side opposite the right
angle. Two HTML encodings of this sentence are given below.

 <p>The <dfn>hypotenuse</dfn> of a right triangle is the side opposite the
right angle. </p>
 <p> The <span style="font-style: italic;">hypotenuse</span> of a right
triangle is the side opposite the right angle.</p>

In this example hypotenuse is the word being defined. It is embedded within
the defining text. The two entities are related by the following
relationship rule: The meaning of the word being defined is precisely what
is being stated in the defining text. Let us call this relationship the
definition relationship. The first encoding identifies the definition
relationship between the word, hypotenuse, and the defining text by
bracketing the defined word within the HTML code <dfn>hypotenuse</dfn>.
The <dfn> element has one meaning; it brackets a word being defined.

The second HTML encoding simply italicizes the word hypotenuse using the
HTML code <span style="font-style: italic;">hypotenuse</span>. It relies on
human intelligence and fully sighted human vision to conclude that an
italicized word within the context of a defining sentence identifies a
definition relationship.  The fact that the particular italicized word
represents a defined term within a definition relationship could not be
determined by a program, because the program would have to understand
English to determine that the author had defined a term. This is beyond the
scope of computer programs.
 Success Criterion (SC) 1.3.1 (Info and Relationships) of Guideline 1.3
applies to these examples. It requires that relationships that are
expressed using presentation can also be programmatically determined.  In
the first encoding the defined term could be detected by a program because
it was bracketed by, the HTML tags, "<dfn>...</dfn>."  One could easily
assign an italic style to the <dfn> element so the running text of the
sentence has normal style and the defined word is italicized. Fully sighted
visual readers could have their familiar reading experience for a
definition relationship, and a program could determine the same
relationship.  In the second encoding a fully sighted visual reader can
perceive the definition relationship from the presentation, but no computer
program can determine the relationship.
 The first encoding passes SC 1.3.1 and the second fails.  This follows
directly from the precise wording of SC 1.3.1 and the meaning of
relationship and programmatically determined.
Received on Tuesday, 18 February 2014 20:10:26 UTC

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