- From: Miles, AJ (Alistair) <A.J.Miles@rl.ac.uk>
- Date: Fri, 1 Oct 2004 13:44:34 +0100
- To: "'public-esw-thes@w3.org'" <public-esw-thes@w3.org>
Who's impressed I got the word 'metaphysical' into that last email? Didn't do a degree in Zoology for nothing you know. Btw for non-RDF folks, an RDF 'resource' is a 'thing' basically. 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 Miles, AJ > (Alistair) > > Sent: 01 October 2004 13:41 > To: 'public-esw-thes@w3.org' > Subject: FW: [Proposal][SKOS-Core] skos:denotes > > > > > > I think what I meant was ... > > If we have two resources: > > ex:resourceA a skos:Concept; > skos:prefLabel 'Alistair Miles'; > skos:scopeNote 'My mate Al.' > . > > ex:resourceB a foaf:Person; > foaf:name 'Alistair Miles'; > foaf:mbox > <mailto:a.j.miles@rl.ac.uk> > . > > ... the burining questions are: > > Are these two resources fundamentally different in nature, or not? > > Are these two resources at different levels of abstraction, or not? > > My point in the last email [1] was that, it *does not* seem > reasonable to > allow for example: > > ex:resourceC a skos:Concept; > skos:prefLabel 'Alistair Miles'; > skos:scopeNote 'My mate Al.'; > a foaf:Person; > foaf:name 'Alistair Miles'; > foaf:mbox > <mailto:a.j.miles@rl.ac.uk> > . > > ... intuitively because properties like 'skos:scopeNote' seem > appropriate to > describe an abstract concept, but not to describe a person. > > I.e. in logic speak the classes skos:Concept and foaf:Person should be > disjoint. > > What Dave said in an earlier email (I think) was that I > should not think of > ex:resourceB as an actual person, but as an abstract entity, > with the same > metaphysical status as ex:resourceA (i.e. they are both abstractions). > > But intuitively I do think of ex:resourceB as an actual > person (should I > change that?), and that feeling is the basis for my assertion > above. And > even if I do accept they are both abstractions, one *feels* to me more > abstract than the other. > > Are we getting closer or farther away? > > Al. > > [1] > http://lists.w3.org/Archives/Public/public-esw-thes/2004Oct/0000.html > > --- > 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 NJ > > Rogers, Learning > > and Research Technology > > Sent: 01 October 2004 12:36 > > To: Miles, AJ (Alistair); 'public-esw-thes@w3.org' > > Subject: RE: [Proposal][SKOS-Core] skos:denotes > > > > > > > > Ok, so you're talking about the class/instance issue, right? > > > > You're saying that OWL classes and foaf classes for example > > can be used in > > the range of the rdf type property. So that a resource may be > > of *type* > > person. > > And you're saying that naturally skos Concept *instances* (e.g. > > myskos:Person - a skos concept that represents the concept of > > a Person > > (?!)) can*not* be used in the range of the rdf type property. > > > > So you're saying, for these cases, that in order to indicate e.g. a > > foaf:Person (class) has some association with > > e.g.myskos:Person (instance) > > we need a skos:denotes property in SKOS Core. > > > > I get this logic. But I still don't get why this is machinery is so > > important. When do we want to query RDF data in a way such > > that we need > > skos:denotes? It must be blindingly obvious, but please point > > it out to me, > > gimme an example!! > > > > /me thinks further: is it that we might want to phrase RDF > > queries such > > that we effectively ask "this foaf:Person class, what > concept does it > > relate to?..." > > > > Thanks > > Nikki > > > > > > > > --On Friday, October 01, 2004 11:57:06 +0100 "Miles, AJ > (Alistair) " > > <A.J.Miles@rl.ac.uk> wrote: > > > > > > > > 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 > > >> > > >> > > > > > > > > > > > ---------------------- > > NJ Rogers, Technical Researcher > > (Semantic Web Applications Developer) > > Institute for Learning and Research Technology (ILRT) > > Email:nikki.rogers@bristol.ac.uk > > Tel: +44(0)117 9287096 (Direct) > > Tel: +44(0)117 9287193 (Office) > > >
Received on Friday, 1 October 2004 12:45:06 UTC