same and synonym Re: IAU thesaurus in RDF (an update)

[Norman Gray]

On 2007 Oct 8, at 18:09, Bernard Vatant wrote:

> So something like the following would be perfectly consistent with  
> both OWL and SKOS semantics
>
> iau:stars   rdf:type   skos:Concept
> cds:stars   rdf:type   skos:Concept
> iau:stars   owl:sameAs   cds:stars
>
> Of course, you might want things more subtle than that, because for  
> some reason you want to declare a mapping without merging the two  
> concepts. In that case you can use SKOS mapping properties, but  
> note that this draft has no formal status whatsoever so far on W3C  
> track. See http://www.w3.org/2004/02/skos/mapping/spec/

In the demo I gave at the ADASS VOEvent BoF, I illustrated how you  
could get this same effect using rdfs:subClassOf:

<ivo://VOcabulary/AOIM#startypevariablenova>
     a skos:Concept;
     skos:broader <ivo://VOcabulary/AOIM#star>;
     rdfs:subClassOf <http://www.ivoa.net/ns/ucd#star.binary.CV.nova> .

<ivo://ivoa/VOcabulary/AAkeys#starsnovaecataclysmicvariables>
     a skos:Concept;
     skos:broader <ivo://ivoa/VOcabulary/AAkeys#stars>;
     rdfs:subClassOf <http://www.ivoa.net/ns/ucd#star.binary.CV.nova>.

<http://www.ivoa.net/ns/ucd#star.binary.CV.nova>
     rdfs:subClassOf <ivo://VOcabulary/AOIM#startypevariablenova>;
     rdfs:subClassOf <ivo://ivoa/VOcabulary/ 
AAkeys#starsnovaecataclysmicvariables> .

(the pairs of subClassOf relations mean you can go both ways).  That  
meant that the SPARQL query

select ?r ?b
where {
   AOIM:startypevariablenova rdfs:subClassOf ?r.
   ?r skos:broader ?b.
}

was able to start from the AOIM vocabulary and find a broader term in  
the A&A vocabulary, using only standard tools.

That has the effect of owl:sameAs[1], but using only an RDFS reasoner.



Rick on 2007 October 9:

> It's the "sameAs" functionality which we need to be able to  
> translate between vocabularies.

We can support a mixture of such direct pairwise mappings, or else go  
via an intermediate vocabulary such as UCDs

> This is all very interesting (seriously!), but it should be clear  
> that there's no way we're going to be able to produce a version of  
> the IAU/IVOA where the ontological hints have been clean up /  
> checked.   We should consider the present content to be informative  
> and condusive to testing ontological analyses with thesauri.  The  
> goal might be to go back and re-check the BT's, NT's, and RT's and  
> maybe even add more info in the next version (or an auxilliary  
> version).

Once it's got into a triple store, it doesn't matter where RDF has  
come from.  Thus it's perfectly practical to have a SKOSified  
vocabulary as one deliverable, and a set of mappings and additional  
annotations in a separate auxiliary deliverable.



All the best,

Norman


[1] perhaps modulo some class-as-instance subtlety

-- 
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Norman Gray  :  http://nxg.me.uk
eurovotech.org  :  University of Leicester, UK