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Re: Southampton Pub data as linked open data

From: Richard Cyganiak <richard@cyganiak.de>
Date: Tue, 29 Jul 2008 11:59:29 +0100
Cc: "John Goodwin" <John.Goodwin@ordnancesurvey.co.uk>, "Chris Wallace" <Chris.Wallace@uwe.ac.uk>, <public-lod@w3.org>, <semantic-web@w3.org>
Message-Id: <2BB87A31-0940-4039-B43A-BBC5F6315943@cyganiak.de>
To: Bijan Parsia <bparsia@cs.man.ac.uk>

Bijan, Knud, Bernard, thanks for the clarification.

I'm indeed surprised! Subclassing rdfs:label is okay in RDFS, and it  
is okay in OWL Full, but it is not allowed in OWL DL.

The RDF consumers I'm working on (RDF browsers and the Sindice engine)  
don't care if you're in OWL DL or not, so I'm tempted to argue that it  
doesn't matter much for RDF publishing on the Web. (IME, on the open  
Web, trust and provenance are much larger issues than inference, and I  
don't believe that the open Web will ever be OWL DL, so why bother.)

Others here will probably have different perspectives on this question.


On 28 Jul 2008, at 17:01, Bijan Parsia wrote:

> On 28 Jul 2008, at 16:23, Richard Cyganiak wrote:
>> On 28 Jul 2008, at 15:52, John Goodwin wrote:
>>>> In an ideal
>>>> world, John would declare pub:name a subproperty of
>>>> rdfs:label, and the tools would infer the rdfs:label value...
>>>> But most clients don't do that yet.
>>> Am I allowed to declare something as subproperty of rdfs:label?
>> As far as I know, yes.
>>> I'm
>>> guessing this is one of those things that is allow in RDF, but not  
>>> in
>>> OWL DL?
>> I would be surprised if that is the case.
> You're surprised.
>> What makes you think so?
> The spec? :) But also you can try one of the species validators.
> (rdfs:label is an annotation property and you are not allowed to  
> subproperty annotation properties in OWL DL)
> http://www.w3.org/TR/owl-semantics/syntax.html#2.1
> """Properties relate individuals to other information, and are  
> divided into four disjoint groups, data-valued properties,  
> individual-valued properties, annotation properties, and ontology  
> properties"""
> Then if you look at the rest of the grammar, you'll see where  
> annotation properties are allowed.
>> Can anyone else comment on this?
>> (FWIW, foaf:name is a subproperty of rdfs:label.)
> And hence, not OWL DL.
> Historywise, this sort of annotation is a kind of metamodeling. At  
> the time, the WebOnt working group (at least the DL contingent)  
> wasn't sure how to handle this (it's not a standard feature of  
> logics, esp. if you give it a strong semantic reading a la OWL  
> Full). So the compromise was to forbid this.
> In OWL 2 (DL), you can get this sort of effect two ways, annotations  
> (which are under discussion and being explored) or by punning  
> classes and individuals (which won't actually help you with the  
> built in vocabulary).
> Typically, subpropertying rdfs:label isn't really a *domain  
> modeling* thing, but an attempt to spec a *presentational* issue  
> (i.e., many UIs exploit rdfs:label, and one wants to indicate which  
> properties should show up in the UI). Thus, there's a bit of tension  
> there.
> HTH.
> Cheers,
> Bijan.
Received on Tuesday, 29 July 2008 11:00:18 UTC

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