- From: Sean Bechhofer <sean.bechhofer@manchester.ac.uk>
- Date: Mon, 17 Nov 2008 17:11:23 +0000
- To: Jens Lehmann <lehmann@informatik.uni-leipzig.de>
- Cc: John Goodwin <John.Goodwin@ordnancesurvey.co.uk>, Chris Bizer <chris@bizer.de>, public-lod@w3.org, Semantic Web <semantic-web@w3.org>, dbpedia-discussion@lists.sourceforge.net
On 17 Nov 2008, at 17:00, Jens Lehmann wrote: > > > Hello John, > > John Goodwin wrote: >> >> Thanks Chris and team for all your hard work getting this done. I do, >> however, have a few comments regarding the OWL ontology. I think in >> general the use of domain and range is perhaps a bit "dubious" in >> that >> for many things I think it is overly specified. I can imagine anyone >> re-using the Dbpedia properties getting some unexpected inferences >> from >> the domain and range restrictions. Also the range restriction seem >> to be >> done as an OWL intersection so if, for example, something has a >> publisher x then x will be inferred to be both a Company and a Person >> which is probably not what you want. Personally, in all but a few >> cases, >> I'd be tempted to generalise or just remove the domain/range >> restrictions. Any thoughts? > > We specified the domains and ranges as disjunctions of classes (not > intersection). See the W3C specification of owl:unionOf [1]. John's comment relates to (at least) the axioms on "publisher": [[ <owl:ObjectProperty rdf:about="http://dbpedia.org/ontology/publisher"> <rdfs:label xml:lang="en">publisher</rdfs:label> <rdfs:domain> <owl:Class> <owl:unionOf rdf:parseType="Collection"> <owl:Class rdf:about="Work"/> <owl:Class rdf:about="Book"/> <owl:Class rdf:about="Newspaper"/> </owl:unionOf> </owl:Class> </rdfs:domain> <rdfs:range rdf:resource="http://dbpedia.org/ontology/Person"/> <rdfs:range rdf:resource="http://dbpedia.org/ontology/Company"/> </owl:ObjectProperty> ]] The semantics of range mean that you have essentially asserted that the range of published is [Person and Company]. If you want the union, you'll have to explicitly use the unionOf constructor here. Cheers, Sean -- Sean Bechhofer School of Computer Science University of Manchester sean.bechhofer@manchester.ac.uk http://www.cs.manchester.ac.uk/people/bechhofer
Received on Monday, 17 November 2008 17:16:40 UTC