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Why not a generic skos:label datatype property? Re: Southampton Pub data as linked open data

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Tue, 29 Jul 2008 16:42:26 +0200
Message-ID: <488F2C52.4050807@mondeca.com>
To: Tim Berners-Lee <timbl@w3.org>
Cc: Richard Cyganiak <richard@cyganiak.de>, Bijan Parsia <bparsia@cs.man.ac.uk>, John Goodwin <John.Goodwin@ordnancesurvey.co.uk>, public-lod@w3.org, semantic-web@w3.org, SKOS <public-esw-thes@w3.org>

Tim Berners-Lee wrote
> 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
Tim, please see my previous message on this. To your request, a while 
ago we made a similar move in Geonames ontology, and have to define a 
OWL-Full ontology importing the OWL-Lite ontology plus the subproperties 
declarations. As said in my previous message I consider this as being a 
suboptimal patch to the fact that the built-in OWL vocabulary does not 
provide any proper way to define a hierachy of name types.
Would you recommend that SKOS vocabulary, for example, defines 
skos:prefLabel and skos:altLabel  as subproperties of rdfs:label in 
order to make Tabulator and the like happy, and hence moving to OWl-Full?
> (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.
Recommending systems built on the semantics of OWL, which are quite hard 
to set up and define properly, to ignore parts of this very semantics 
sounds to me as a strange recommendation coming from the very W3C top :-)

But : as said before, the real issue is that you ask both vocabulary 
publishers and implementers to hack the standards semantics, default any 
proper way in those standards to deal with names.
What I suggest here (with cc to SKOS forum)  is to define somewhere a 
standard generic label datatype property, which could be easily refined 
in specific types of labels while keeping in OWL-DL; making everybody 
happy. The most natural place to do that seems to be SKOS namespace.
Here is the proposal

skos:label      a    owl:DatatypeProperty
skos:prefLabel      rdfs:subPropertyOf      skos:label
skos:altLabel      rdfs:subPropertyOf      skos:label
pub:name     rdfs:subPropertyOf      skos:label

Applications and vocabularies wanting to stick to OWL-DL would use 
skos:label and its extensive subproperties instead of rdfs:label
RDFS-only applications would just have to add
skos:label      rdfs:subPropertyOf       rdfs:label

What do people think?


PS : just reading John's answer ... I guess he would be very happy with 
such a solution

> Tim
> 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.
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*Bernard Vatant
*Knowledge Engineering
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Received on Tuesday, 29 July 2008 14:43:14 UTC

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