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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: Mon, 27 Aug 2018 01:46:04 +0000
To: public-dxwg-wg@w3.org
Message-ID: <issue_comment.created-416091796-1535334364-sysbot+gh@w3.org>
There is nothing that forces anyone to resolve a dct:type object reference and do any inferencing over it.

If you chose to load both the dcterms RDFS model and resolve the dct:type reference and find the RDFS model for the referred object, then you would naturally have to accept the intention of the data publisher (not the DCAT specification) that any skos:Concepts are indeed "units of thought" that represent (and entail) rdfs:Class

Distributed reasoning means there must be sophisticated contract that actually makes URI references to objects, intrinsically as instances of things, link to a class model.  

TopBraid, for example, has a bunch of built in assumptions that some graphs are loaded - and this is a mixture of explicit OWL imports, (perhaps also TBC controlled imports smuggled into comments in TTL files?) , and reflection based on "magic" patterns in file names in projects, whose Eclipse UI controlled open-or-closed state determines if they are loaded.  Its kind of horrible, but seems a fair reflection of the reality that the application context is responsible for determining the graph to reason over, and any entailment regimes. 

So, I dont see a reason why the project discussed cannot make its mind up that all references must have a rdfs:Class axiomitisation,  and that resources resolved from URIs they use are constrained to be OWL-DL.  I think to flip the argument on its head, it seems unwise to force such assumptions on everyone. DCAT users should be free to use whatever reasoning and entailments they choose. 

That said, the existence of examples that do implicity rely on (perfectly legal) OWL punning interpretations should carry an explanation that some examples do assume an environment where punning between skos:Concepts and rdfs:Class is allowed, and that DCAT itself does not dictate this either way.





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Received on Monday, 27 August 2018 01:46:06 UTC

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