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Re: OWL species and subproperties of rdfs:label

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Tue, 9 Jan 2007 16:45:35 -0500
Message-Id: <425BE63C-C0D9-467E-B1BE-766E31FFB0CD@gmail.com>
Cc: bernard.vatant@mondeca.com, der@hplb.hpl.hp.com, semantic-web@w3.org, timbl@w3.org, marc@geonames.org, public-owl-dev@w3.org
To: Michael Schneider <m_schnei@gmx.de>


On Jan 9, 2007, at 4:21 PM, Michael Schneider wrote:

> What I have found in OWL1.1 is this "punning" mechanism: When you  
> have some class C, you can then also give this same name, "C", to  
> some instance. So one could perhaps come to the conclusion, that  
> one can just attach the datatype property to the /instance/ C,  
> which is of course formally allowed in OWL/DL. But, as I understand  
> punning correctly, there is no semantical connection between Class 
> (C) and Individual(C) (see [1, 3.3]) - it just seems to be meant  
> as a form of name "overloading". And this would /not/ solve the  
> above problem! (It could instead easily lead to some hard to find  
> errors: One might intend to add some property to a class, but, in  
> fact, the property is added to an instance, which happens to have  
> the same name.)

You are correct. This is true of the punning mechanism in general. It  
was believed that this mechanism was possible to implement in the  
short run, and seemed better than the alternative of having to use  
annotation properties. That said, there will likely be a working  
group on OWL 1.1 and hopefully feedback from people using the feature  
will indicated whether, on the whole, its benefits outweigh the  
problems generated by it.

>
>> In the spec its use is (halfway)  constrained to be a datatype  
>> property because when specified via the  Label() construct its  
>> value must be a "constant".
>
> Another, more exotic use of rdfs:label, which comes to my mind,  
> would be to label a resource with some /graphical object/ instead  
> of a text label. Not, that I would argue for doing so, but people  
> will perhaps come to this idea, and perhaps some people already did  
> so. In this case, the label would better be an URL to the graphical  
> resource instead of a text string. And then, a datatype property  
> would not be the right thing, again.

Agreed.

It would be useful to see how prevalent this usage is. There are a  
couple of alternatives that come to mind.

1) Allow subproperty statements relating annotation properties to  
each other, but forbid that they participate in restrictions. I think  
this would mean that there would no need to have the reasoner  
involved with these properties, but queries for property values would  
need to take the subproperty statements into account. Some DL person  
will surely explain to me why this can't work....

2) Allow rdfs:label to be declared either an ObjectProperty or a  
DatatypeProperty and have this declaration trump any built in  
AnnotationProperty  declaration. The downside of this is that an  
owl:imported ontology could declare rdfs:label to be the other type  
and render the ontology inconsistent.

-Alan
Received on Tuesday, 9 January 2007 21:46:46 GMT

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