- From: David Booth <david@dbooth.org>
- Date: Wed, 24 Jun 2009 13:41:46 -0400
- To: Pat Hayes <phayes@ihmc.us>
- Cc: James Prentice <prentice.j.a@gmail.com>, semantic-web@w3.org
On Wed, 2009-06-24 at 09:58 -0500, Pat Hayes wrote: > > On Jun 23, 2009, at 6:18 PM, James Prentice wrote: [ . . . ] > > If I declare > > the foaf namespace and then refer to foaf definitions in my ontology, at > > some point the foaf ontology has to be loaded. > No, it doesn't. That is the point. You may be being misled by > referring to foaf 'definitions'. OWL and RDF don't have definitions, > just assertions (sentences, axioms, 'facts') There are no definitions > that have to be loaded or used. However, if you want your reasoner to make use of the additional semantics implied by a particular URI, such as an OWL URI, then the reasoner needs to know about them. In short, if you are using terms from an ontology, there are *three* things you may wish to do: 1. Namespaces can provide convenient abbreviations for long URIs -- nothing more. 2. You may wish to load the ontology into your reasoner along with your other RDF data. This may permit your reasoner to produce more interesting entailments. 3. You may wish to load particular "semantic extensions" (see http://www.w3.org/TR/rdf-mt/#MonSemExt ) into your reasoner or choose a reasoner that has built-in support for the semantic extensions that you wish to use, such as OWL semantics. This also may permit your reasoner to produce more interesting entailments. Except for namespaces, this process is illustrated in figure 2 at http://dbooth.org/2009/denotation/#rdfsem -- David Booth, Ph.D. Cleveland Clinic (contractor) Opinions expressed herein are those of the author and do not necessarily reflect those of Cleveland Clinic.
Received on Wednesday, 24 June 2009 17:42:27 UTC