some thoughts about ISSUE 35 ConceptSchemeContainment

Issue description: http://www.w3.org/2006/07/SWD/track/issues/36

Synopsis of the issue: SKOS provides a mechanism to indicate that a 
concept is contained in a concept scheme (the property skos:inScheme), 
but it is nontrivial to define such containment for relation between 
concepts (e.g. broader/narrower).

The whole notion of containment in a thorny one in a Semantic Web 
setting. Note that OWL ontologies do not have a language construct for 
this. It is understandable that some way of saying that "these elements 
are part of my vocabulary" is useful for vocabulary owners. However, it 
is doubtful whether we can try to solve this at the level of SKOS. The 
reasons for wanting to define containment typically have to do with 
issues such as trust and rights. In my view such mechanisms should be 
provided at the general RDF level. We shouldn't try to solve this issue 
with a special-purpose construct in SKOS.

I therefore propose to deprecate the property skos:inScheme.

I suggest to include in our documents guidelines for how to handle 
containment issues, e.g. by making using of rdf:isDefinedBy or by 
relying on through guidelines for querying.

I could also go one step further and propose to drop also the class 
skos:ConceptScheme and the property skos:hasTopConcept. Instead of 
skos:ConceptScheme SKOS users could just use the OWL construct 
owl:Ontology, which also provides an import construct (owl:import). 
Finding the top concepts could just be handled at the query level. 
However, skos:ConceptScheme (and skos:hasTopCncept) could be just viewed 
as a useful documentation vehicle.

Guus

Received on Wednesday, 25 July 2007 19:59:31 UTC