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RE: ERT WG: Agenda for teleconference on Wednesday 17 October 2012

From: Samuel Martín <samuelm@dit.upm.es>
Date: Thu, 18 Oct 2012 11:37:16 +0200
To: <kvotis@iti.gr>, "'Shadi Abou-Zahra'" <shadi@w3.org>
Cc: "'ERT WG'" <public-wai-ert@w3.org>
Message-ID: <031701cdad14$29f055a0$7dd100e0$@dit.upm.es>
Dear Kostas, all,

I am providing this as followup of yesterday's conference, regarding the use
of rdf:ID or rdf:about to identify the Assertions. Shadi pointed out the
rdf:about in an Assertion identifies the assertion object, not the TestCase.
Agreeing with that, then I wondered whether it should be rdf:ID or
rdf:about. As from RDF/XML Syntax Specification (
http://www.w3.org/TR/REC-rdf-syntax/#section-Syntax-ID-xml-base ): 

>> The rdf:ID attribute on a node element (not property element, that has
another meaning) can be used instead of rdf:about and gives a relative RDF
URI reference equivalent to # concatenated with the rdf:ID attribute value.
So for example if rdf:ID="name", that would be equivalent to
rdf:about="#name". rdf:ID provides an additional check since the same name
can only appear once in the scope of an xml:base value (or document, if none
is given), so is useful for defining a set of distinct, related terms
relative to the same RDF URI reference.

A post from IBM developerWorks
(http://www.ibm.com/developerworks/xml/library/x-tiprdfai/index.html)  sheds
a nice insight into the choice between both: 

>> As for choosing between rdf:ID and rdf:about, you will most likely want
to use the former if you are describing a resource that doesn't really have
a meaningful location outside the RDF file that describes it. Perhaps it is
a local or convenience record, or even a proxy for an abstraction or
real-world object (although I recommend you take great care describing such
things in RDF as it leads to all sorts of metaphysical confusion; I have a
practice of only using RDF to describe records that are meaningful to a
computer). rdf:about is usually the way to go when you are referring to a
resource with a globally well-known identifier or location.

So, the differences are:
1. Lexical & syntactic: rdf:ID should be specified as an xml ID (ie, with no
leading hash), and acts as a URI reference to the element within the
document. Meanwhile, rdf:about is a URI: it can be an absolute URI, or a
relative one (which is resolved against the document base URL, obtained from
either context or xml:base), or a URI reference (that is, with a leading
2. Semantic: rdf:ID behaves as an xml ID (I grasp this from context, I have
not found the specific reference where rdf:ID is declared as being an xml
ID), so it must be unique in the context of an RDF/XML document with the
same xml:base URI. Given that, it seems more reasonable to use rdf:ID to
specify an assertion, as it would not appear again elsewhere in an EARL
report. Nonetheless, it is also perfectly correct to use an rdf:about, and
even to include several Assertion elements with the same rdf:about (it would
just add more statements to the rdf node designed by the Assertion...
disregarding the result could either be valid EARL or not).
3. Pragmatic: in practice, rdf:ID is used when you are trying to provide
*the* definition for the object (including when you are providing the
representation from a real-world entity), rdf:about when  you are referring
to an external entity with a well-known URI. That said, this is just a
matter of convenience.

To sum it up, both are equivalent from and RDF point of view (although
rdf:ID could seem slightly more appropriate here, just as a practical
matter). In any case, proper syntax needs to be used ( #name or a full URI
for rdf:about, name for rdf:ID), and unicity must be preserved in case
rdf:ID is chosen.



-----Mensaje original-----
De: kvotis@iti.gr [mailto:kvotis@iti.gr] 
Enviado el: miércoles, 17 de octubre de 2012 10:48
Para: Shadi Abou-Zahra
Asunto: Re: ERT WG: Agenda for teleconference on Wednesday 17 October 2012

Dear Shadi, all

please find attached an EARL example from our assessment tool. I have tried
to make it as simple as possible by trying also to fulfill Shadi's
recommendations. However more details could be provided during our telco



> The next teleconference is scheduled for Wednesday 17 October 2012 at:
>   * 14:30 to 15:30 Central European Time (CET)
>   * 09:30 to 10:30 North American Eastern Time (ET)
>   * 06:30 to 07:30 North American Pacific Time (PT)
> Please check the World Clock Meeting Planner to find out the precise 
> date for your own time zone:
>   - <http://www.timeanddate.com/worldclock/meeting.html>
> The teleconference information is: (Passcode 3794 - "ERWG")
>   * +1.617.761.6200
>   * SIP / VoIP - http://www.w3.org/2006/tools/wiki/Zakim-SIP
> We also use IRC to support the meeting: (http://irc.w3.org)
>   * IRC server: irc.w3.org
>   * port: 6665
>   * channel: #er
> #1. Welcome
> #2. EARL 1.0 Test Suite
>   - status check on test suite development
>   - <http://www.w3.org/WAI/ER/EARL10/tests/>
> #3. Accessibility Support Database
>   - preview on early conceptual draft
>   - <http://www.w3.org/WAI/ACT/asd>
> #3. Website Accessibility Conformance Evaluation Methodology 1.0
>   - commenting period ending soon
>   - <http://www.w3.org/TR/WCAG-EM/>
> #4. Techniques For Accessibility Evaluation And Repair Tools 1.0
>   - revival of a historical document
>   - <http://www.w3.org/TR/2000/WD-AERT-20000426>
> #5. Next Meeting
> Regards,
>    Shadi
> --
> Shadi Abou-Zahra - http://www.w3.org/People/shadi/ Activity Lead, 
> W3C/WAI International Program Office Evaluation and Repair Tools 
> Working Group (ERT WG) Research and Development Working Group (RDWG)
Received on Thursday, 18 October 2012 09:52:02 UTC

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