Re: ConceptScheme as a subset of another?

Dear Mike,

Sorry for the delay. To answer your specific questions:


> I understand that the skos:inScheme property can be used to say a 
> concept is in a particular ConceptScheme and this can be used many times 
> to say the same concept is in many schemes. 


Exact.


> I can't say that one 
> ConceptScheme is in another can I?


You cannot say this, at least using the SKOS model or another standard Semantic Web vocabulary. See [1].
We have discussed that in the WG, but the requirement was not clear enough at the time.
The only standard way is really to have your concept belonging to several schemes at a same time.


> Is there any sensible way I can support these subsets?


Now, you could still create your own property to represent scheme inclusion, and equip it with semantics that help you implement the multiple inScheme statement trick.
With OWL 2, this is doable:
1. you can introduce, say, an ex:subScheme property
2. you can define a property chain axiom [2] that combines it with skos:inScheme: 
[] rdfs:subPropertyOf skos:inScheme; owl:propertyChainAxiom (skos:inScheme ex:subScheme ).

With this, if A is a sub-scheme of B, whenever you have c1 skos:inScheme A, then you would also have c1 skos:inScheme B if you use an appropriate reasoner.
But of course this solution is not guaranteed to work well when others consume data that you wouldn't have "completed" youself beforehand, as it would rely on an adhoc property...

Cheers,

Antoine

[1] http://www.w3.org/TR/skos-primer/#secextension
[2] http://www.w3.org/TR/owl2-new-features/#F8:_Property_Chain_Inclusion


>  
> 
>  
> 
> ------------------------------------------------------------------------
> 
> *Van:* public-esw-thes-request@w3.org 
> [mailto:public-esw-thes-request@w3.org] *Namens *Mike Thacker
> *Verzonden:* dinsdag 30 juni 2009 18:25
> *Aan:* SKOS
> *Onderwerp:* ConceptScheme as a subset of another?
> 
>  
> 
> Hello
> 
> I'm getting my head around SKOS with a view to seeing how well we can 
> represent UK public sector vocabularies hosted by esd.org.uk 
> <http://esd.org.uk> in SKOS and derive online viewers and other human 
> and machine readable resources from the RDF.
> 
> My initial question relates to whether or not SKOS supports what esd 
> knows as "subsets".  For example these two online viewers:
> 
>     * Subject vocabulary: http://www.esd.org.uk/standards/ipsv/viewer/
>     * Service vocabulary: http://www.esd.org.uk/standards/lgsl/viewer/
> 
> both feature drop down lists towards the top left of the page.  >From 
> the drop-down list you can select a named "subset" which contains some 
> of the concepts from the main list (eg you can limit UK local government 
> services to those delivered in Scotland).
> 
> I understand that the skos:inScheme property can be used to say a 
> concept is in a particular ConceptScheme and this can be used many times 
> to say the same concept is in many schemes.  I can't say that one 
> ConceptScheme is in another can I?
> 
> Is there any sensible way I can support these subsets?
> 
> Thanks in advance
> Mike
>

Received on Wednesday, 15 July 2009 12:37:01 UTC