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Re: [ALL, OEP] Relationship between OWL and other ontology modelling

From: Deborah L. McGuinness <dlm@ksl.Stanford.EDU>
Date: Tue, 20 Apr 2004 15:43:27 -0700
Message-ID: <4085A78F.6030606@ksl.stanford.edu>
To: ewallace@cme.nist.gov
Cc: public-swbp-wg@w3.org

concerning the notion of qualified cardinalities and role hierachies and 
restrictions (whether they are local with value restrictions or global 
with range restrictions),

it is true that you can end up modeling information concerning qualified 
cardinalities using role hierarchies, restrictions, and regular 
cardinality restrictions, but it does get ugly.

for example, consider the case where i want to have at least 2 siblings 
who are doctors on some new class.
i can create a role  hasSibling and create a subrole of hasSibling (on 
which i will put a value or range restriction).
call the subrole hasSiblingDoc.
then in my newclass, i can have a DOCTOR value restriction on 
hasSiblingDoc   (or i could have made the global range restriction on 
hasSiblingDoc be DOCTOR)
and i can put an atmost 2 cardinality restriction on hasSiblingDoc on 
the newclass.

I could similarly do the same kind of modeling for at least 2 siblings 
who are doctors on another newclass2

The ugliness arises because i have to make the new subroles with the new 
either local value restrictions or global range restrictions.

also, from a computational perspective - the reasoner still has to do 
the right counting work at the superrole.
for example, if i had another subrole called hasSiblingLawyer  and had
another newclass - newclass3  that had at least 2 hasSiblingLawyer and 
also had atleast 2 hasSiblingDoctor,
then a reasoner should be able to determine some cardinality restriction 
information on the hasSibling property of newclass3.  clearly it is 2   
but if one knows anything about the disjointness of the value 
restrictions or range restrictions  (for example, if i knew that doctor 
and lawyer were disjoint)  then i could determine that the atleast 
restriction was 4.
also, if i know something about uniqueness of known fillers or if i know 
some particular filler is NOT an instance of the class in the range 
restriction, then i can also increase the min cardinality.

for example, if i know that Joe is a filler of the property 
hasSiblingDoctor  and I know that Joe is NOT a lawyer, then I know that 
Joe must be distinct from the 2 fillers of the hasSiblingLawyer property 
and I know that the minimum cardinality of hasSibling on newClass3 must 
be at least 3. 


ewallace@cme.nist.gov wrote:

>I think Alan meant to send this to the SWBPD list.
>In response to his comment.  UML Associations are typically binary and
>scoped to the classes at both end-points (so in this sense they are innately
>qualified).  However, Association names must be unique within a Package. It would 
>take an intelligent mapping to aggregate semantically similar Associations together 
>into OWL ObjectProperties, although I agree that this is the "right way" to do it.  
>The mapping rules that I have seen recently in fact do the opposite, they even 
>mangle DatatypeProperty names for corresponding UML attributes by pre-pending them 
>with a UML class name.  
>Regarding work arounds for qualified cardinality:  Cannot one get the
>expressiveness of Qualified Cardinality by using subProperties of a 
>common property and placing local restrictions on the cardinality of those?
>Is that ugly or problematic?
>----- Begin Included Message -----

 Deborah L. McGuinness 
 Associate Director Knowledge Systems Laboratory 
 Gates Computer Science Building, 2A Room 241 
 Stanford University, Stanford, CA 94305-9020 
 email: dlm@ksl.stanford.edu
 URL: http://ksl.stanford.edu/people/dlm
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801 705 0941
Received on Tuesday, 20 April 2004 18:43:26 UTC

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