- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Thu, 2 Jan 2003 18:58:37 -0500
- To: Jeff Heflin <heflin@cse.lehigh.edu>, WebOnt <www-webont-wg@w3.org>
> > >- Language structure, para. 3, "An OWL ontology consists of an optional >ontology element.": The element shouldn't be optional. If the person >want their document to be an ontology, it should have an ontology >element. Of course, they are free to define classes and properties in >other documents, and they may not define any classes and properties in a >document with owl:Ontology, but neither of these should be encouraged. encouraging the use of owl:ontology is okay by me, Requiring it did not receive consensus in the WG, and thus the reference should not make it required. > >- Class elements, sameAs bullet: owl:sameAs when applied to a class DOES >NOT have the same semantics as owl:sameClassAs. owl:sameAs is a synonym >for sameIndividualAs which when applied to classes say they are the same >individuals and thus have the same properties, including e.g. the same >values for rdfs:label. owl:sameClassAs only means that the two classes >have the same extension (i.e., the same members) and says nothing about >what properties the two classes have in common. we need to get this right. I can live either way - but we have made Semantics the normative for this, and it agrees with what Jeff says above (as I understand it) so Ref should be changed. > >- Property elements, last para. "A property is a binary relation that >may or may not be defined in the ontology." Did the WG ever discuss >whether or not it was legal to reference a class or property that wasn't >defined in the ontology? I certainly would not support this. It makes it >even easier for errors to creep into ontologies. I must be missing something, we had long discussion about reference to things outside current ontology during the imports debate in particular. I can certainly say in document A that something is a B:foo (foo a class) where B is a different document and no imports is specified. Do you mean something different by "not defined in the ontology"? > >- The RDF Schema for OWL should be textually included in the document, >so that if people print it out, they get it as well great idea > >Here are some additional comemnts on >http://www.daml.org/2002/06/webont/owl > >- We should import the Dublin Core schema. i.e. add: > <imports rdf:resource="http://purl.org/dc/elements/1.1/"> >to the ontology header. I endorse this idea - consistent with previous decisions re: Dublin Core, and makes it easier to use DC in OWL. -- Professor James Hendler hendler@cs.umd.edu Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Thursday, 2 January 2003 18:58:42 UTC