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RE: ISSUE-65 (excess vocab): REPORTED: excessive duplication of vocabulary

From: Boris Motik <boris.motik@comlab.ox.ac.uk>
Date: Thu, 22 Nov 2007 10:58:47 -0000
To: "'Jeremy Carroll'" <jjc@hpl.hp.com>
Cc: "'OWL Working Group WG'" <public-owl-wg@w3.org>
Message-ID: <000801c82cf6$a819cfe0$2711a8c0@wolf>

Hello,

But dc:creator is usually an annotation property, right? I was here referring to object and data properties.

Also, you are free to come up with whatever usage restrictions/semantics for OWL 1.1 Full. OWL 1.1 DL, however, must be two-sorted:
the interpretation domains of the abstract and the concrete domain must be disjoint. This is a hard decidability requirement. Thus,
in OWL 1.1 DL, whenever you use a piece of vocabulary, you really need to know whether this usage refers to the abstract or the
concrete domain. Given this fundamental requirement of OWL 1.1 DL, you have two possibilities.

1. You can type the usage of the vocabulary. In this case, you can write both

ObjectSomeValuesFrom( dc:creator A )

and

DataSomeValuesFrom( dc:creator A ).

Because the usage is typed, you know that in the first case you really meant "the variant of dc:creator which connects two
individuals", and in the second case you really meant "the variant of dc:creator which connects an individual with a data value".

This is what we did in the proposed OWL 1.1 spec, but people didn't like it and they deem it to be ugly.


2. You can require a strict separation of the vocabulary. In this case, you can write

SomeValuesFrom( dc:creator A );

however, in order to know how to interpret dc:creator, you need to have an explicit type for it, which can be *either*
owl:ObjectProperty *or* owl:DatatypeProperty.

This is what I proposed as a potential solution to the ugliness problem, but alas, people again seem not to like it.

Well, I don't see a third possibility (other than lumping the concrete and the abstract interpretation together, which is just not
an option for OWL 1.1 DL); however, if someone has an idea how to get out of this conundrum, I'm all ears.

	Boris

> -----Original Message-----
> From: Jeremy Carroll [mailto:jjc@hpl.hp.com]
> Sent: 22 November 2007 10:42
> To: Boris Motik
> Cc: 'OWL Working Group WG'
> Subject: Re: ISSUE-65 (excess vocab): REPORTED: excessive duplication of vocabulary
> 
> Boris Motik wrote:
> 
> > I do not expect that users will actually want to use the same URI as both
> > an object and a data property.
> 
> My users do.
> 
> e.g. dc:creator is sometimes used with a string, being the name, and
> sometimes with a more complex object
> 
> Perhaps my users don't count?
> 
> Jeremy
Received on Thursday, 22 November 2007 10:59:31 GMT

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