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