Re: New BNB sample data available

>     Hi Jeff,
>
>     As this coordination issue is complex indeed, this was not handled in SKOS. Instead it relies on specific extensions to be designed--this is MADS/RDF [1] is made for, in fact!
>
>
> There are complexities in the syntax and semantics of subdivided, coordinated, compound, and faceted headings that aren't really addressed by the MADS/RDF proposal.
>
> I have a presentation covering some aspects of the semantics of subdivided and faceted headings at ISKO-UK conference in London this year.
>
> One thing to be careful of with prefLabel is that SKOS does not explicitly express the constraint that prefLabel's must be unique in a given scheme. This restriction is tricky to express, even with OWL 2 Key Properties, as prefLabels are annotation properties, and are thus not covered by the OWL 2 semantics. The constraint can be expressed for skosxl, as skosxl:prefLabel is an ObjectProperty, and literalForm is a DataProperty (though there's a little bit of trickiness needed to make sure that two Labels with the same literalForm aren't used as skosxl:prefLabel for different concepts). Also, if the same label is used for two concepts, HasKey will infer that they are owl:sameAs.
>


Hi Simon,

I think we agree. There are probably areas of coordination that are not properly tackled by MADS/RDF (but I prefer to leave it to Kevin's mail for this discussion) and there are SKOS spec parts that can't be represented properly in OWL [1].
The question if it helps already to solve important problems. I believe it does--and as for SKOS, it is an RDF vocabulary, so you can still extend it to match your own more precise needs. I'm looking forward to see your presentation (online), btw.

Antoine

[1] At the time we did not have the resource for coming with a proper OWL2 ontology (OWL2 was not a standard then anyway) but we also thought it would fail capturing everything. If you're interested in the matter, there was since a blog post by Paul Hermans on that: http://www.proxml.be/users/paul/weblog/d1855/Where_OWL_fails_another_OWL_arises.html

Received on Sunday, 6 February 2011 13:55:23 UTC