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Re: declaredAs

From: Matthew Horridge <matthew.horridge@cs.man.ac.uk>
Date: Wed, 25 Jul 2007 15:13:33 +0100
Message-Id: <D1C1028E-5318-4406-8C4E-E50C0F08F395@cs.man.ac.uk>
To: Owl Dev <public-owl-dev@w3.org>

Revisiting the issue of declaring and typing, because it is causing  
problems - in particular backwards compatibility with OWL 1.0

Below is a message to the list from Evren Sirin

> On 26 Jan 2007, at 20:22, Evren Sirin wrote:
> In OWL 1.0, there is not really a difference between declarations  
> and typing. Having a triple <p, rdf:type, owl:ObjectProperty>   
> constitutes its declaration (as on object property in this case). I  
> agree that requiring declaration for every resource is not a good  
> idea. OWL-DL requires every resource to be typed and it turns out  
> that many ontologies out on the Web fall into OWL-DL expressivity  
> but do not meet this requirement. But now are we separating  
> declarations from typing and say that declarations are not required  
> but typing still is?
> And if I understand the mapping from RDF graphs to OWL 1.1  
> correctly, an ontology that has just the above triple (or any any  
> number of rdf:type triples where the object is one of  
> owl:ObjectProperty, owl:DatatypeProperty, or owl:Class) will be  
> mapped to an empty OWL 1.1 ontology. I don't think this is a  
> desired result.

I am in complete agreement with the last point.  There are plenty  
(enough to cause problems) of ontologies that just consist of  
rdf:type triples such as A rdf:type owl:Class.  As Evren points out,  
when parsed, these documents result in empty ontologies, which is  
less than desirable - users of tools such as editors find this  
confusing and don't expect it.  Does anyone have any suggestions  
about how to resolve this?


Received on Wednesday, 25 July 2007 14:15:02 UTC

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