- From: Thomas Baker <tbaker@tbaker.de>
- Date: Tue, 20 Oct 2009 15:42:15 -0400
- To: SWD Working Group <public-swd-wg@w3.org>
- Cc: David Wood <dwood@zepheira.com>
Dear all, I would like to draw your attention to a discussion on the dc-architecture list of two proposals for using SKOS properties to represent constructs of the DCMI Abstract Model in RDF [1]: 1. To use skos:inScheme instead of dcam:memberOf to relate a value to a DCAM Vocabulary Encoding Scheme. 2. To use skos:prefLabel instead of rdf:value to relate a value to a DCAM Value String. See the attached summary (below) of discussion of Proposal #1. Specifically, the discussion of #1 has noted that the domain of skos:inScheme was left unspecified in order to provide the flexibility to extend a concept scheme with classes of resource other than skos:Concept -- even though the wording "A SKOS concept scheme can be viewed as an aggregation of one or more SKOS concepts." seems to suggest that a SKOS concept scheme is indeed intended to be understood specifically as a set of concepts. The DCMI community would appreciate feedback on this issue, either on this list or on dc-architecture, as appropriate. Tom [1] https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0910&L=DC-ARCHITECTURE&P=802 On Tue, Oct 20, 2009 at 03:15:11PM -0400, Thomas Baker wrote: > Date: Tue, 20 Oct 2009 15:15:11 -0400 > From: Thomas Baker <tbaker@tbaker.de> > To: DCMI Architecture <dc-architecture@jiscmail.ac.uk> > Subject: Proposal #1: replace dcam:memberOf with skos:inScheme > Content-Type: text/plain; charset=us-ascii > > On Oct 15, 2009, at 1:25 AM, Thomas Baker wrote: > > >David Wood suggests two changes in how DCAM constructs are > > >represented in RDF [1]: > > > > > >1. Instead of using dcam:memberOf to relate a value to a > > > DCAM Vocabulary Encoding Scheme [1, section 4.5], David > > > suggests using skos:inScheme. > > Points made about proposal #1 to date: > > -- The range of skos:inScheme is skos:ConceptScheme [3]. > > -- The domain of skos:inScheme was left unspecified [2] in > order to provide the flexibility to extend a concept scheme > with classes of resource other than skos:Concept (i.e., the use > of skos:inScheme does not imply that the subject is a concept). > > -- That said, the SKOS Reference does indeed say [3]: > > "A SKOS concept scheme can be viewed as an aggregation of one > or more SKOS concepts." > > implying that a SKOS concept scheme is intended to be > understood as a set of SKOS concepts. However, the wording > "can be viewed" seems vague enough so as not to actually > _contradict_ the notion of a skos:ConceptScheme as a set of > things of any type (i.e., instances of classes other than > skos:Concept). > > -- Bernard elaborates on the consequences of entailments [5]: > > > #1 : Complete agreement, being aware of consequences. If > > the domain of skos:inScheme is open, its range is > > skos:ConceptScheme, so using this property entails that any > > dcam:VocabularyEncodingScheme used as the object of > > skos:inScheme is a skos:ConceptScheme. The following > > logical step is to declare dcam:VocabularyEncodingScheme as > > a subclass of skos:ConceptScheme. And the next one is > > asking what is specific to this subclass. If there is no > > specificity, dcam:VocabularyEncodingScheme could as well > > (should?) be replaced in the abstract model by > > skos:ConceptScheme. Do you want to go this far in > > entailments? > > In other words, replacing dcam:memberOf with skos:inScheme > suggests that we also declare: > > dcam:VocabularyEncodingScheme rdfs:subClassOf skos:ConceptScheme > > and that we replace the notion of VES in DCAM with > that of SKOS concept scheme. > > -- dcam:memberOf could be declared a subproperty of skos:inScheme: > > dcam:memberOf rdfs:subClassOf skos:inScheme > > My personal position, in light of the above: > > -- That DCMI should declare both: > > dcam:VocabularyEncodingScheme rdfs:subClassOf skos:ConceptScheme > > and > > dcam:memberOf rdfs:subPropertyOf skos:inScheme > > -- That the DCAM Description Set model [4] should be revised to > use skos:ConceptScheme instead of (or rather in addition to) > dcam:VocabularyEncodingScheme, underlining the equivalence of > the two and emphasizing that a SKOS concept scheme is > understood _not_ to be limited to SKOS concepts. > > -- That DCAM should be revised to use skos:inScheme instead of > dcam:memberOf -- _unless_ we do in fact see a significant difference > between a SKOS concept scheme and a VES. > > I would want to get some input on whether sub-property relations > is the way to do this (as opposed to, say, owl:equivalentProperty [6]). > > Am I overlooking anything? > > Tom > > [1] http://dublincore.org/documents/dc-rdf/#sect-4 > [2] http://www.w3.org/TR/skos-reference/#L2805 > [3] http://www.w3.org/TR/skos-reference/#schemes > [4] http://dublincore.org/documents/abstract-model/ > [5] https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0910&L=dc-architecture&P=2739 > [6] http://www.w3.org/TR/owl-ref/#equivalentProperty-def -- Thomas Baker <tbaker@tbaker.de>
Received on Tuesday, 20 October 2009 19:42:54 UTC