Re: Extending RDFS, property-classes

On Tue, Feb 10, 2009 at 12:09 AM, Peter Ansell <ansell.peter@gmail.com> wrote:
> 2009/2/10 Alan Ruttenberg <alanruttenberg@gmail.com>:
>>
>> Hello Richard,
>>
>> I find your remark very odd, and more demonstrative of a lack of
>> experience than an accurate perception of the state or vision of the
>> Semantic Web. Certainly the lack of customers using OWL becomes a
>> self-fulfilling prophecy when such a point of view is held.
>>
>> OWL is widely deployed in the area I work on the Semantic Web for
>> science, with our own Neurocommons being a 400M triple store expressed
>> in OWL and many other projects using OWL. Within biomedicine OWL is
>> commonly used, with the OBO ontologies, the NCI thesaurus all
>> available in OWL and SNOMED on the way. It would make no sense for any
>> of these projects to use RDF or even RDFS. For one thing there is no
>> way for anything to be incorrect (from a logical point of view) in
>> RDFS, and you might be aware of a certain penchant scientists have for
>> theories that can be refuted.
>
> I was under the impression there was no way in OWL to say that
> something was possibly incorrect? Could you give an example so I can
> get my head around what you said more clearly?

What I mean is that it is possible to detect an inconsistency in the
set of axioms expressed as OWL. A very simple example is to say that
some individual is both a instance of a class and its complement.
Another thing that can be detected is when there is a cardinality that
is violated. We used inverse functional properties and cardinality
constraints to find mistakes in accession number cross references in
some work we called "debugging the bug"
http://bio.freelogy.org/wiki/Debugging_the_bug

There are only trivial inconsistencies detectable in RDFS, such as
malformed literals.

>> Even within RDF usage, there are bits of OWL vocabulary that are quite
>> popular and are used extensively, for example (for better or worse)
>> owl:sameAs and owl:inverseFunctionalProperty
>
> Are people using these properties in applications without following
> and/or understanding the complete OWL specification?

Some are, some not.

-Alan


> Cheers,
>
> Peter
>

Received on Tuesday, 10 February 2009 05:17:28 UTC