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Re: Use cases wrt Dataset proposal (UC 1.5, UC 5.2)

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 1 Mar 2012 13:16:50 -0600
Cc: Dan Brickley <danbri@danbri.org>, RDF WG <public-rdf-wg@w3.org>
Message-Id: <9BDE8204-DD8B-4855-84F3-15218BFABB11@ihmc.us>
To: Antoine Zimmermann <antoine.zimmermann@emse.fr>

On Mar 1, 2012, at 2:50 AM, Antoine Zimmermann wrote:

> Le 01/03/2012 08:48, Dan Brickley a écrit :
>> 
>> 
>> On Wednesday, 29 February 2012, Antoine Zimmermann wrote:
>> 
>> [...]
>> 
>> If I say in an ontology document:
>> 
>> <>  owl:imports <http://zimmer.aprilfoolsreview.com/antoine#me>.
>> 
>> then, what I get, according to the OWL specs, is an ontology with
>> the content of http://zimmer.aprilfoolsreview.com/antoine included,
>> in spite of <http://zimmer.aprilfoolsreview.com/antoine#me> denoting
>> a foaf:Person.
>> 
>> Please take a look at the OWL 2 spec section 3.2 to check.
>> 
>> 
>> Why should an ontology's RDF description not include information
>> about real-world entities?
> 
> On the contrary, it should. It is not what I said. I say that the import mechanism does not care about what kind of entity is denoted by the IRI used with owl:imports.

No, it does care. If http-range-14 is correct, then that URI has to denote an information resource. 

> In the example above, the owl:imports statement implies (in the OWL 2 RDF based semantics, which is certainly the one the RDF WG is most interested in) that <http://zimmer.aprilfoolsreview.com/antoine#me> is an ontology, but after the import is effective via a HTTP lookup, it will be inferred that <http://zimmer.aprilfoolsreview.com/antoine#me> is a foaf:Person as well. This is consistent, as nothing says that ontologies cannot be people,

Actually it is impossible for an OWL ontology document (which is what gets retrieved) to be a person, and there might even be true ontologies out there which assert this. 

This discussion is clearly deeply involved with the whole http-range issue. If we accept the TAG ruling on http-range-14, at least for now, and if the http retrieval in this example returns a 200-level coded response without any redirection, then we do have to assume that the URI denotes an "information resource", ie a Web document, more or less. And hence that it cannot be a person (or maybe better, it would be false and dangerous to move ahead with any infernce that was based on such a claim, as it is false and very liable to be contradicted by an accepted and authoritative ontology somewhere.) So I dont thikn we can be so blasé as you would like us to be about situations like this. 

Pat


> but it may seem weird to some people. But look at the following example:
> 
> 
> <> owl:imports <http://xmlns.com/foaf/0.1/#stuff> .
> <http://xmlns.com/foaf/0.1/#stuff> owl:sameAs <http://dbpedia.org/ontology/> .
> 
> This will import the FOAF ontology (assuming the application is doing a HTTP lookup). However, this:
> 
> <> owl:imports <http://dbpedia.org/ontology/> .
> <http://xmlns.com/foaf/0.1/#stuff> owl:sameAs <http://xmlns.com/foaf/0.1/#stuff> .
> 
> will import the dbpedia ontology.
> 
> In spite of owl:sameAs being formally interpreted as identity, these two ontologies will eventually have very different inferences. This is because the mechanics behind owl:imports is not part of the model theory of OWL.
> 
>> 
>> Dan
>> 
>> 
>> 
>> 
>> At the very least, if we mandate this, then we need to clarify the
>> semantic role of "label" URIs in datasets.
>> 
>> Pat
>> 
>> ------------------------------__------------------------------ IHMC
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>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> -- Antoine Zimmermann ISCOD / LSTI - Institut Henri Fayol École
>> Nationale Supérieure des Mines de Saint-Étienne 158 cours Fauriel
>> 42023 Saint-Étienne Cedex 2 France Tél:+33(0)4 77 42 83 36
>> Fax:+33(0)4 77 42 66 66 http://zimmer.__aprilfoolsreview.com/
>> <http://zimmer.aprilfoolsreview.com/>
>> 
> 
> 
> -- 
> Antoine Zimmermann
> ISCOD / LSTI - Institut Henri Fayol
> École Nationale Supérieure des Mines de Saint-Étienne
> 158 cours Fauriel
> 42023 Saint-Étienne Cedex 2
> France
> Tél:+33(0)4 77 42 83 36
> Fax:+33(0)4 77 42 66 66
> http://zimmer.aprilfoolsreview.com/
> 
> 

------------------------------------------------------------
IHMC                                     (850)434 8903 or (650)494 3973   
40 South Alcaniz St.           (850)202 4416   office
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Received on Thursday, 1 March 2012 19:17:39 GMT

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