Re: [OEP] "Classes as values": comments on draft

* Miles, AJ (Alistair)  <A.J.Miles@rl.ac.uk> [2004-04-29 15:36+0100]
> 
> Sorry, resending this correcting some N3 syntax mistakes ...
> 
> I believe the best way to express the fact that a particular image depicts a

("a particular thing...")

> thing which is a member of the class of Lions would be to say (this is the
> FOAF model):
> 
> LionImage
> 	a	AnimalImage;
> 	foaf:depicts	[a	Lion].

For 'best way', I'm reading, 'most appropriate idiom' rather than 'best
RDF property'. There will likely be various other RDF vocabs that adopt
a similar approach. The basic idea with foaf:topic is to be able to say
that some Document is 'about' (has as a subject/topic/etc) some
particular thing. We recently extended this by creating
foaf:primaryTopic, for cases where a Document has a very obvious
dominant topic.

> Lion
> 	a	owl:Class;
> 	subClassOf	Mammal.
> 
> Mammal	a	owl:Class.
> AnimalImage	a	owl:Class.
> 
> 
> The alternative way of expressing similar information is to use the
> dc:subject property along with the SKOS model [2] for describing concepts
> that are intended to act as 'subjects' or 'topics' for information
> resources.

Yes. I think the work we do here in the THES/PORT tf will need to do two
things. We should articulate a vocabulary in the broader/narrower/etc
tradition that is sufficient to represent thesauri *as thesauri* (SKOS
is an excellent candidate there imho), but we
should also go deeper into an explanation into these two fundamentally
different (and complimentary) approaches to topic description. 

> LionImage
> 	a	AnimalImage;
> 	dc:subject	LionConcept.
> 
> LionConcept
> 	a	skos:Concept;
> 	skos:prefLabel	'Lions';
> 	skos:broader	MammalConcept.
> 
> MammalConcept
> 	a	skos:Concept;
> 	skos:prefLabel	'Mammals';
> 	skos:narrower	LionConcept.
> 
> The SKOS vocab already defines a class 'Concept' and a set of properties for
> organising concepts into a hierarchy, without demanding that the hierarchy
> implies a subclass relationship.  I refer the WG to the document [2] which
> outlines the SKOS-Core schema, although you should currently ignore the
> final section on 'using SKOS-Core with DC and FOAF' as this will change
> shortly to be in line with the model of usage that I have briefly described
> here.

The thread I started on public-esw-thes yesterday picks up this line of 
enquiry too, using a geographical example. 
http://lists.w3.org/Archives/Public/public-esw-thes/2004Apr/0021.html

This reminds me, I was going to propose to the WG that the
thesaurus/porting tf adopt that mailing list as it's main home, with 
periodic reports back here. Al, everyone, what do you think?

Dan

ps. http://www.w3.org/2001/sw/Europe/talks/200404-synthesis/ is my 
brief talk from tuesday's SWAD-Europe meeting. Has a few more notes on
these issues.

pps. does someone have a pointer to the latest work here on
wordnet-in-rdf?