Re: [Use Case] ETRI-UC1: Filling the holes of OWL ontology

At 19:57 +0900 12/11/05, Minsu Jang wrote:
>This use case is too obvious that it might not be obvious to cast it as a
>use case, but I'll try.
>
>** ETRI-UC1: Filling the holes of OWL
>
>When building ontologies using OWL, we usually come up with such relations
>or classes that are difficult or impossible to express in OWL, which creates
>vocabulary holes in the ontologies. The most representative hole is the set
>of relations that can be defined by chained properties[1][2]. For example,
>with OWL alone, you cannot describe "uncle" relation, which is the
>composition of "father" and "brother" relation, into the family ontology.
>With rules, it's trivial to describe the relations defined by chained
>properties. As such, RIF will be an essential semantic web language that
>complements and extends OWL.
>
>[1] OWL Web Ontology Language Use Cases and Requirements, W3C Recommendation
>10 Feb 2004
>[2] Benjamin N. Grosof, Ian Horrocks, Raphael Volz, and Stefan Decker.
>Description logic programs: Combining logic programs with description logic.
>In Proc. of the Twelfth International World Wide Web Conference (WWW 2003),
>pages 48-57. ACM, 2003.
>
>Regards,
>Minsu
>

Actually, let us be clear here - it is easy to come up with a 
definition of uncle in OWL and one can even rule out inconsistent 
cases using a DL reasoner (for example,  I could discover it was 
inconsistent for Bob to be in a "no siblings" class if I knew Bob was 
in the uncle class).  What each of the various approaches can do with 
"uncle" is actually quite complicated, gets into issues of grounded 
literals and other such things (i.e. many rule systems can't find all 
uncles because you may need unsafe reasoning to remain decidable) -- 
I don't object to the thrust of the use case about doing things OWL 
cannot, but this canard about "not doing uncle" is a misunderstanding 
of something Ian Horrocks said in some email to the Web Ontology 
Working Group (i.e. it's been taken out of context)  and needs to be 
much more carefully elucidated if you want to use it in a use case...

-- 
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Received on Sunday, 11 December 2005 17:39:38 UTC