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Re: Southampton Pub data as linked open data

From: Tim Berners-Lee <timbl@w3.org>
Date: Tue, 29 Jul 2008 16:08:33 +0200
Cc: Bijan Parsia <bparsia@cs.man.ac.uk>, "John Goodwin" <John.Goodwin@ordnancesurvey.co.uk>, "Chris Wallace" <Chris.Wallace@uwe.ac.uk>, <public-lod@w3.org>, <semantic-web@w3.org>
Message-Id: <00301C76-28AD-4FBB-A1B0-E413A80C4E65@w3.org>
To: Richard Cyganiak <richard@cyganiak.de>

Making something like pub:name a subProperty of rdfs:label is  
essential for the Tabulator for example to know it can use names as  
labels in the UI.  So please do it

(and don't duplicate the data in pub:name and rdfs:label in the data!)

Presumably OWL DL systems can be built to ignore the rdfs:subClassOf  
fact when they do OWL-DL reasoning on the data.


On 2008-07 -29, at 12:59, Richard Cyganiak wrote:

> 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.
> Richard
> 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 14:09:19 UTC

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