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XHTML 2.0 - dfn : Content model and usability

From: Karl Dubost <karl@w3.org>
Date: Tue, 5 Jul 2005 10:48:59 -0400
Message-Id: <9a08242558f16a9e27451a19faa823af@w3.org>
Cc: www-html@w3.org
To: www-html-editor@w3.org

Hi,

We had a discussion on a French Web developer mailing-list  
[pompeurs][1] about dfn. The first comment was about the understanding  
of the definition in the specification. The second comment was about  
usability and to know if it was very useful.


* Understanding DFN

[[[
9.4. The dfn element

The dfn element contains the defining instance of the enclosed term.

* Attributes

The Common collection

A collection of other attribute collections, including: Bi-
directional, Core, Edit, Embedding, Events, Forms, Hypertext, I18N,
Map, and Metainformation.

* Example

An <dfn id="def-acronym">acronym</dfn> is a word formed
from the initial letters or groups of letters of words in a set
phrase or series of words.
]]] -  
http://www.w3.org/TR/2005/WD-xhtml2-20050527/mod- 
text.html#edef_text_dfn


Maybe the first sentence should be something like:

The dfn element contains a word (or a group of words) being defined by  
one or more sentences.


* Usability

It may be good to give usability examples of this element. Why is it  
useful to use this element?

1. Human Usability.

Defined once somewhere with an "id" (mandatory ?), the definition can  
be linked from another document, or another part of the text referring  
to this definition. It's human usability. Though someone could argue  
that:

	An <span id="def-acronym">acronym</span> is a word
	formed from the initial letters or groups of letters
     of words in a set phrase or series of words.

is not a loss in usability at all. The dfn element having not direct  
benefits for the user. Even better someone could choose to do.

	Blah blah blah. <span id="def-acronym">An acronym is a word
	formed from the initial letters or groups of letters
     of words in a set phrase or series of words.</span> Blah blah blah.

then it gives the same functionality for the user and it's easier to  
extract the _exact_ definition.


2. Machine Usability.

Is dfn useful for a machine, a semantics analyzer agent or just a tool  
to create a list of definition, a glossary from one or a series of  
page. If we take the example given in XHTML 2.0 right now, I would be  
inclined to say no.

	An <span id="def-acronym">acronym</span> is a word
	formed from the initial letters or groups of letters
     of words in a set phrase or series of words.

There's a missing element to be really useful.

	- A definition can be created by more than one sentence.

	<span clas="def">An <span id="def-acronym">acronym</span>
	is a word formed from the initial letters or groups
	of letters of words in a set phrase or series of words.
	Another sentence. Yet another sentence.</span>

	- A definition can be included in a more general paragraph.

	Some prose. <span clas="def">An <span id="def-acronym">acronym</span>
	is a word formed from the initial letters or groups
	of letters of words in a set phrase or series of words.</span>
	Some another prose.

Without the span here, it's impossible for an agent to extract the  
definition and make a glossary. The user, for sure, could have the  
choice to do what I have just done, add span in the text. But that  
would be with a random definition of the class name or the way to do  
it.

So I'm not sure if dfn element is useful being underspecified.

I propose either
	- to drop it from the specification
	- to add an element making possible to use it for automatic purpose.


[1]: http://fr.groups.yahoo.com/group/pompeurs/

-- 
Karl Dubost - http://www.w3.org/People/karl/
W3C Conformance Manager
*** Be Strict To Be Cool ***
Received on Tuesday, 5 July 2005 14:48:24 GMT

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