- From: Miles, AJ (Alistair) <A.J.Miles@rl.ac.uk>
- Date: Fri, 1 Oct 2004 11:57:06 +0100
- To: "'public-esw-thes@w3.org'" <public-esw-thes@w3.org>
How about this for an argument as to why resources of type skos:Concept are at a different level of abstraction to, say for example, resources of type foaf:Person ... You would not say that a 'scopeNote' or a 'definition' is a property of a person. However, you might reasonably say that an 'email address' or 'date of birth' is a property of a person. Al. --- Alistair Miles Research Associate CCLRC - Rutherford Appleton Laboratory Building R1 Room 1.60 Fermi Avenue Chilton Didcot Oxfordshire OX11 0QX United Kingdom Email: a.j.miles@rl.ac.uk Tel: +44 (0)1235 445440 > -----Original Message----- > From: public-esw-thes-request@w3.org > [mailto:public-esw-thes-request@w3.org]On Behalf Of Dave Reynolds > Sent: 30 September 2004 18:38 > To: Matthews, BM (Brian) > Cc: 'public-esw-thes@w3.org' > Subject: Re: [Proposal][SKOS-Core] skos:denotes > > > > Matthews, BM (Brian) wrote: > > > As I interpret this, this gives the best semantics I know of for > > Thesaurus concepts - a concept's denotation is "the set of > resources > > which are classified under that concept" (my words). This is quite > > different from the intended use in Ontologies, where instances are > > "supposed" to stand for "real-world" things (with suitable > philosophical > > quotation marks). > > I agree with that summary of the semantics of Thesaurus > concepts but I'm > not so sure ontologies are that different. Sure in > philosophical terms > ontologies are more than that, as you say, but in practical > RDFS and OWL > terms a class is just a set of instances and an instance is just a > "resource". It so happens that OWL gives you some machinery > for identifying > the class of a resource by its properties, and RDFS gives you > less, but the > difference between those and your semantics for Thesaurus > concepts is just > a matter of expressivity rather than of fundamental nature. > > Personally I find this article nicely captures this view that > they are just > a continuum with different expressivity and degree of formality: > http://www.metamodel.com/article.php?story=20030115211223271 > > > So I think that the word "denotes" to connect a > thesaurus-theoretic and > > a ontology-theoretic point of view is dangerous - as in logic > > and mathematics this usually signifies semantics - we are > not (should > > not) be saying that the class provides a semantics for the concept. > > Agreed. > > > An alternative term then? skos:classifierFor is perhaps > most precise, > > though a bit awkward. But I prefer it to the alternatives we have > > seen so far which imply some kind of semantic relationship. > > To me that also implies a semantic relationship but maybe > that's just me. > > > Nikki says: > > > >>Or is this debate really about the fact that we want to stick some > >>machinery capable of SKOS<->OWL stuff in SKOS-Core right > now, so that > >>SKOS-Core stands in its own right allowing us to tackle > SKOS-Mapping > >>separately? > > > > > > As far as I see - yes! The use of this property is to do > the modelling > > task of relating SKOS and OWL - and SKOS-mapping should be separate. > > To me there's no particular difference between saying that two SKOS > Concepts are trying to model the same "real world" thing and > saying that a > SKOS Concept and an OWL Class are trying to model the same > "real world" > thing. So I'm with Nikki, it seems odd putting it in the core > rather than > in mapping. > > > To turn to the specifics of the proposal (to start a new > controversy), > > does it make sense (particularly when taking a point of view that > > we are providing a classifier for an RDF resource) for this property > > to be a functional property? This would mean if two > resources have the > > same classifier, they can be identified. This may not make sense. > > My vote would be "no". > > For example, you might have a SKOS Thesaurus concept > "my:Person" an RDF > Class foaf:Person and an RDF Class drc:Person. They are all > trying to model > the same real world notion but in different ways (e.g. > drc:Person might > have cardinality restrictions on properties that foaf:Person > has nothing to > do with). As I understand it, the point of this property is > to be able to > say "my:Person and foaf:Person are both attempts to model the > same thing" > without carrying any semantics such as cardinality restrictions. > > It would be reasonable to also want to say "my:Person and > drc:Person are > both attempts to model the same thing" without that implying that > drc:Person = foaf:Person (with all that would entail from the formal > semantics of the foaf and drc schemas). > > Cheers, > Dave > >
Received on Friday, 1 October 2004 10:57:39 UTC