Re: Drilling into the LOD Cloud

----- "Damian Steer" <d.steer@bristol.ac.uk> wrote:

> From: "Damian Steer" <d.steer@bristol.ac.uk>
> To: "Kingsley Idehen" <kidehen@openlinksw.com>
> Sent: Monday, September 29, 2008 7:30:30 AM GMT +10:00 Brisbane
> Subject: Re: Drilling into the LOD Cloud
>
> On 28 Sep 2008, at 19:01, Kingsley Idehen wrote:
> 
> >
> > Dan Brickley wrote:
> >> Kingsley Idehen wrote:
> >>>
> >>> Then between UMBEL and OpenCyc:
> >>>
> >>> 1. owl:sameAs
> >>> 2. owl:equivalentClass
> >>
> >> If these thingies are owl:sameAs, then presumably they have same IP- 
> >> related characteristics, owners, creation dates etc?
> >>
> >> Does that mean Cycorp owns UMBEL?
> > Dan,
> >
> > No, it implies that in the UMBEL data space you have equivalence  
> > between Classes used to define UMBEL subject concepts (subject  
> > matter entities) and OpenCyc.
> 
> I think Dan's point is that owl:sameAs is a very strong statement, as 
> 
> illustrated by the ownership question. If opencyc:Motorcyle  
> owl:equivalentClass umbel:Motorcycle then they have the same  
> extension. Informally, any use you make of one as a class can be  
> replaced by the other without changing the meaning of the whole.  
> However if the are owl:sameAs they name the same thing, so  
> dc:creationDate, dc:creator, cc:license, rdfs:isDefinedBy etc etc are 
> the same for each, which strike me as unhelpful side effects.  
> owl:equivalentClass is the vocabulary mappers' friend :-)

That is fine for classes, but how do you map individuals without metadata side-effects? Is there a need for a metadata term type which is locked to the URI that it is defined against and does not carry with sameAs?

A reasoner could implement such a thing for terms which it knows are not to be applied against other URI's (above the individual/class model).

Peter

Received on Sunday, 28 September 2008 23:52:08 UTC