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A comment on rdfms-reification-required

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Thu, 08 Nov 2001 09:38:23 +0000
Message-ID: <3BEA528F.7070803@hplb.hpl.hp.com>
To: rdf core <w3c-rdfcore-wg@w3.org>
I received the following comment on the proposed resolution of rdfms-reification 
-required from Wolfram:



Here is an example of RDF without bagID, where the reification is
required to (re-)construct the context of the "comment" property to be
able to answer, for example, a query that tries to retrieve the correct
comment for each different s:property that is attached to "Author".



<?xml version="1.0"?>

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:s="http://description.org/schema/"
xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/TR/1999/PR-rdf-schema-19990303#"

 >


<rdfs:Resource rdf:ID="Author"/>

<rdf:Description about="#Author">
<s:name>Skolem</s:name>
<comment rdf:parseType="Literal">This is his last name</comment>
</rdf:Description>

<rdf:Description about="#Author">
<s:firstname>Toralf</s:firstname>
<comment rdf:parseType="Literal">This is his first
name</comment>
</rdf:Description>

</rdf:RDF>


[Note, however, that folks may consider this bad modelling practice and
say that this comment should actually be attached to a bagID. However, I
am pretty sure that there are cases where it is useful to be able to see
that a number of statements have been made "together in one description"
to be able to interpret, for example, lexically identic utterances that
are made in two or more descriptions in the appropriate context (ok, we
do not have the vocabulary yet to allow for such subtleties, and as
notions such as extensibility, scope and reification are not covered in
the current MT, we will not have it for some time, so now it may be
considered irrelevant)]

In the light of this comment, I've modified the proposed resolution:

Proposal:
    The WG resolves that a parser is not required to always emit statements
    representing a bag of reified statements for each Description
    element.  A parser SHOULD emit statements describing a bag of reifed
    statements when an rdf:bagID is present in the description element.
    It SHOULD be possible to instruct a parser to emit bags of
    reified statements for all description elements.

Brian
Received on Thursday, 8 November 2001 04:43:26 EST

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