- From: Miles, AJ \(Alistair\) <A.J.Miles@rl.ac.uk>
- Date: Mon, 10 Oct 2005 17:12:28 +0100
- To: "Pete Johnston" <p.johnston@UKOLN.AC.UK>, <DC-RDF-TASKFORCE@JISCMAIL.AC.UK>
- Cc: <public-esw-thes@w3.org>
Hi Pete, > Without taking a position one way or the other ;-) I'd just note that > "pattern 2" is embedded in the DCAM > > http://dublincore.org/documents/abstract-model/ > > > Each resource may be a member of one or more classes. Note > that where > the resource is a value, the class is referred to as a vocabulary > encoding scheme. > > so it's not just the mapping to RDF which would have to change. > Yup :) > Also I don't think that the examples of "pattern 1" in the > draft DCQ-RDF > doc ever say that the object of the rdfs:isDefinedBy triple is the URI > of the scheme. > > Section 2.3.2 suggests that "URI1" in that example is _not_ the URI of > the scheme: the URI of the Class is the URI of the scheme > ("If there is > some RDF Class given to identify the Scheme...."). Quoting from [1] section 2.3 ... 'In the case where there is a URI, specifying the object we want to use in it's relation with the scheme, we could make an rdfs:isDefinedBy arc pointing to that URI. Such a triple of RDF(S) properties hanging off a resource is what one may call: Poor Man's Structured Values' ? Oh, another thought, the only way I can see 'Vocabulary Encoding Scheme' mapping to RDF as is, without changing the AM, is to model them as RDF datatypes. I.e.: <http://www.example.com/somedoc> dc:subject 'D08.586.682.075.400'^^dcterms:MESH. Although I certainly can't claim to understand the finer points of how an RDF datatype maps a set of literal values to resources, the notion of a datatype in RDF seems to fit best with the notion of 'encoding' as it is described in the DCMI AM. Would it be possible to allow both e.g. ... <http://www.example.com/somedoc> dc:subject 'D08.586.682.075.400'^^dcterms:MESH. ... and e.g. ... <http://www.example.com/somedoc> dc:subject <http://purl.org/dc/terms/MESH/D08.586.682.075.400>. ... where there is also ... <http://purl.org/dc/terms/MESH/D08.586.682.075.400> rdfs:label 'Formate Dehydrogenases'; rdf:value 'D08.586.682.075.400'; rdfs:isDefinedBy dcterms:MESH; . ... to live side-by-side? In this case, the last bit of RDF could be used to define the literal-to-resource mapping via the rdf:value (or some other) property? And it would seem reasonable to then also state things like... <http://purl.org/dc/terms/MESH/D08.586.682.075.400> a skos:Concept; skos:prefLabel 'Formate Dehydrogenases'; skos:altLabel 'Formate Hydrogenlyases'; skos:altLabel 'NAD-Formate Dehydrogenase'; skos:scopeNote 'Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but...'; skos:historyNote '91(80); was see under ALDEHYDE OXIDOREDUCTASES 1980-90'; skos:broader <http://purl.org/dc/terms/MESH/D08.811.682.075>; . ...? Also, the pattern: <http://www.example.com/somedoc> dc:subject 'D08.586.682.075.400'^^dcterms:MESH. ... seems to also match closely the XML encoding of qualified DC, using xsi:type. That's all I have for now, cheers, Al. [1] http://dublincore.org/documents/2002/05/15/dcq-rdf-xml/ > > Pete >
Received on Monday, 10 October 2005 16:14:06 UTC