Re: DBpedia 3.2 release, including DBpedia Ontology and RDF links to Freebase

On 17 Nov 2008, at 17:00, Jens Lehmann wrote:

>
>
> Hello John,
>
> John Goodwin wrote:
>>
>> Thanks Chris and team for all your hard work getting this done. I do,
>> however, have a few comments regarding the OWL ontology. I think in
>> general the use of domain and range is perhaps a bit "dubious" in  
>> that
>> for many things I think it is overly specified. I can imagine anyone
>> re-using the Dbpedia properties getting some unexpected inferences  
>> from
>> the domain and range restrictions. Also the range restriction seem  
>> to be
>> done as an OWL intersection so if, for example, something has a
>> publisher x then x will be inferred to be both a Company and a Person
>> which is probably not what you want. Personally, in all but a few  
>> cases,
>> I'd be tempted to generalise or just remove the domain/range
>> restrictions. Any thoughts?
>
> We specified the domains and ranges as disjunctions of classes (not
> intersection). See the W3C specification of owl:unionOf [1].

John's comment relates to (at least) the axioms on "publisher":

[[
<owl:ObjectProperty rdf:about="http://dbpedia.org/ontology/publisher">
<rdfs:label xml:lang="en">publisher</rdfs:label>
	<rdfs:domain>
		<owl:Class>
			<owl:unionOf rdf:parseType="Collection">
				<owl:Class rdf:about="Work"/>
				<owl:Class rdf:about="Book"/>
				<owl:Class rdf:about="Newspaper"/>
			</owl:unionOf>
		</owl:Class>
	</rdfs:domain>
	<rdfs:range rdf:resource="http://dbpedia.org/ontology/Person"/>
	<rdfs:range rdf:resource="http://dbpedia.org/ontology/Company"/>
</owl:ObjectProperty>
]]

The semantics of range mean that you have essentially asserted that  
the range of published is [Person and Company]. If you want the  
union, you'll have to explicitly use the unionOf constructor here.

Cheers,

	Sean

--
Sean Bechhofer
School of Computer Science
University of Manchester
sean.bechhofer@manchester.ac.uk
http://www.cs.manchester.ac.uk/people/bechhofer

Received on Monday, 17 November 2008 17:16:40 UTC