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Re: [dxwg] Use of dct:type with both Class and Concept

From: Rob Atkinson via GitHub <sysbot+gh@w3.org>
Date: Fri, 17 Aug 2018 08:28:05 +0000
To: public-dxwg-wg@w3.org
Message-ID: <issue_comment.created-413795569-1534494484-sysbot+gh@w3.org>
Really interested in the take of others here - there are a couple of ways of looking at this - but I have never been able to find a cogent argument why we shouldnt assume that a rdfs:Class is actually a type of skos:Concept - classes are nothing more that concepts that define sets of instances. 

It seems to be explicitly supported in OWL 2 as "punning" [https://www.w3.org/2007/OWL/wiki/Punning]

It seems a perfectly natural Use Case to me to model skos:Concepts as types in systems, then generate rdfs: and owl Class models only if and when we need to model additional behaviours.

skos:Concept is relevant for "soft-typing" and rdfs:Class for hard-typing - and the equivalence is actucally a useful thing.

Is OWL-Full really a problem? I think not for several reasons:
1) I dont see evidence that OWL-DL (or any other flavour) inferencing is happening at run-time across distributed systems - all "semantic web" implementations I have see cache any models they want to use.
2) There is currently no way of telling a client, not specification, constraining referenced models to be any particular profile of OWL - so no assumptions can be made anyway
3) With negotiation-by-profile the same concept can be served with a graph that conforms to SKOS, RDFS, OWL-DL, OWL-Full, SHACL and any other specific profile needed by a client.

IMHO there is a need to provide a specific example of the problem and why its a problem, and how to handle the use cases of soft-typing.

My feel here, although I can prove it, is that negotiation by profile and OWL 2 punning are two sides of the same coin - implementation and theory,  and essentially we can get out of the bind by the URI dereferencing architecture - OWL-DL reasoners can ask for the metaclass representation they want.

Default behaviour for OWL - i.e. if a client asks for OWL perhaps an OWL-DL representation SHOULD be returned.  I dont know if the profile guidance or content negotiation scope will allow us to go into this platform specific detail - or where and who in W3 cares about the general architecture of distributed OWL models?


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Received on Friday, 17 August 2018 08:28:06 UTC

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