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RE: [Moderator Action] RE: SKOS Public Working Drafts

From: Miles, AJ \(Alistair\) <A.J.Miles@rl.ac.uk>
Date: Tue, 2 Aug 2005 14:48:19 +0100
Message-ID: <677CE4DD24B12C4B9FA138534E29FB1D0ACCB9@exchange11.fed.cclrc.ac.uk>
To: "Mark van Assem" <mark@cs.vu.nl>
Cc: <public-esw-thes@w3.org>

Hi Mark,

> But why not just have an inverse of hasTopConcept, e.g. 
> isTopConceptOf? In any case I think the subPropertyOf relationship 
> should be the other way around.
> 
> This pops up the question with me whether it should be good practice 
> to always provide all the inverses of all object properties.

Dan Connolly has found that inverse properties are actually costly for implementers [1].  I can see it both ways - that in some situations having inverse properties adds convenience, and in others it makes things more complicated.  So I'm not sure what our position should be re inverse properties in SKOS Core, I'm interested to hear other's experiences.

> - the note properties do not have domain and range declared for them
> - the note/label properties have no domain defined for them (I would 
> expect skos:Concept?)

The note properties have domain rdf:Resource, because we didn't want to constrain their use.  We anticipated that some note properties would be useful with e.g. RDF properties and RDFS classes (as e.g. SKOS Core uses skos:definition on it's own properties and classes).

The note properties have no range because we're currently allowing either literals or resources in the range, according to the patterns described in [2].  Again, I look forward to hearing practical feedback on whether this type of flexibility proves too complex or costly to implement.

> However, if there are any 
> particular semantics or rules that could be expressed in OWL, 
> I'd be more than happy to have them added.  Should we declare 
> that {skos:semanticRelation a owl:ObjectProperty.} for example?
> 
> Would there be a reason not to declare it for all object properties?
> 

Maybe I should put together a proposal that adds OWL datatype property and object property type statements for SKOS Core properties where appropriate?

Cheers,

Al.

[1] http://lists.w3.org/Archives/Public/public-esw-thes/2005Mar/0020.html
[2] http://www.w3.org/TR/swbp-skos-core-guide/#secdocumentation
Received on Tuesday, 2 August 2005 13:48:26 GMT

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