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Re: A Dublin Core with RDF datatypes use case

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Thu, 22 Aug 2002 10:28:56 +0300
To: "RDF Core" <w3c-rdfcore-wg@w3.org>, "ext Dave Beckett" <dave.beckett@bristol.ac.uk>
Message-ID: <mxyrlqJq32SV.xZXRnPLQ@mail.nokia.com>


Thanks, Dave.

Your examples are very similar to the ones I am now
using in the updated DT (almost) WD. I'll add them to
the DC use case appendix.

Pat is now reviewing the latest revision of the WD and
should post it to the list in time for Friday's telecon. In
the meantime, if anyone wants to see the latest snapshot,
it's at http://www-nrc.nokia.com/sw/rdf-datatyping.html

In a nutshell, it's the stake-in-the-ground, but with the
explicit typed literal nodes and untidy literals (the latter
now being considered both a requirement of OWL as well
as being the majority preference of the RDF community).

Note that it is less than half the size of the previous
revision, owing to the fact that it is based on the
existing rdf:type and rdfs:range semantics.

This updated (almost) WD should be considered a
proposal to be ratified by the WG and is not (yet)
presumed to reflect WG consensus. It's in WD form
to save editing time and effort so that when the WG
signs off on it, it's ready for publication.

Cheers,

Patrick

_____________Original message ____________
Subject:	A Dublin Core with RDF datatypes use case
Sender:	ext Dave Beckett <dave.beckett@bristol.ac.uk>
Date:		Thu, 22 Aug 2002 10:16:26 +0300



Brian asked me about Dublin Core and datatypes and to make a use case
that shows the kind of thing that might be used.

I took a look at Dublin Core's

  Guidelines for implementing Dublin Core in XML
  http://dublincore.org/documents/2002/07/23/dc-xml-guidelines/

which in section 5.3 has an XML record with XSI types.  The result is
quite close to RDF/XML with datatypes, so I've created what I think
the equivalent would be.

I've used a new rdf:dtype attribute with URIs as values instead of
xsi:type and qnames - this is just my expectation that we use URIs,
not qnames in RDF to identify stuff.  This syntax detail is NOT the
point of the example.

In my opinion, the value of the dc:title element (RDF property) below
has no extra information and the DC community would not expect that
the value would be unique such that another dc:title with the same
value would mean it was the same.

However, for <dc:subject rdf:dtype="&dcterms;DDC">062</dc:subject>
the use of the dcterms DDC - Dewey Decimal Code - is known by the
definition in the DC terms definition to be unique, so that these
values would mean the same concept in DDC.

Dave

---

<?xml version="1.0"?>
<!DOCTYPE rdf:RDF [
  <!ENTITY dcterms 'http://purl.org/dc/terms/'>
]>
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:dcterms="http://purl.org/dc/terms/">

  <rdf:Description rdf:about="http://example.org/something/">

    <dc:title>
      UKOLN
    </dc:title>
    <dcterms:alternative>
      UK Office for Library and Information Networking
    </dcterms:alternative>
    <dc:subject>
      national centre, network information support, library
      community, awareness, research, information services,public
      library networking, bibliographic management, distributed
      library systems, metadata, resource discovery,
      conferences,lectures, workshops
    </dc:subject>
    <dc:subject rdf:dtype="&dcterms;DDC">
      062
    </dc:subject>
    <dc:subject rdf:dtype="&dcterms;UDC">
      061(410)
    </dc:subject>
    <dc:description>
      UKOLN is a national focus of expertise in digital information
      management. It provides policy, research and awareness services
      to the UK library, information and cultural heritage communities.
      UKOLN is based at the University of Bath.
    </dc:description>
    <dc:description xml:lang="fr">
      UKOLN est un centre national d'expertise dans la gestion de l'information
      digitale.
    </dc:description>
    <dc:publisher>
      UKOLN, University of Bath
    </dc:publisher>
    <dcterms:isPartOf rdf:dtype="&dcterms;URI">
      http://www.bath.ac.uk/
    </dcterms:isPartOf>
    <dc:identifier rdf:dtype="&dcterms;URI">
      http://www.ukoln.ac.uk/
    </dc:identifier>
    <dcterms:modified rdf:dtype="&dcterms;W3CDTF">
      2001-07-18
    </dcterms:modified>
    <dc:format rdf:dtype="&dcterms;IMT">
      text/html
    </dc:format>
    <dcterms:extent>
      14 Kbytes
    </dcterms:extent>

  </rdf:Description>
</rdf:RDF>
Received on Thursday, 22 August 2002 03:30:03 EDT

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