[protege-discussion] OWL2 Classes

[Jim Tivy]

Timothy

 

"better to think of myns:Dog as representing the class of all animals that
happen to be dogs. "

 

Yes, OWL2 Class entities and Class hierarchy with SubClassOf are the
recommended way to represent Concepts and "refined" child Concepts - but how
do I attach my properties to the Class since the class is not an individual?
Assuming BroadTerm and NarrowTerm are subsumed by SubClassOf

 

properties:

-        Scope Node

-        Broad Term

-        Narrow Term

-        Related Terms

-     Use

 

 

 

From: protege-discussion-bounces at lists.stanford.edu
[mailto:protege-discussion-bounces at lists.stanford.edu] On Behalf Of Timothy
Redmond
Sent: March-17-12 7:15 AM
To: protege-discussion at lists.stanford.edu
Subject: Re: [protege-discussion] OWL2 Classes

 





 Individual(myns:Dog)

InClass(myns:Dog,Term)

ObjectPropertyAssertion(myns:HasChild,myns:Boxer,myns:Dog)


It could be that this is what you really want to say.  But to me it seems
better to think of myns:Dog as representing the class of all animals that
happen to be dogs.  A myns:Boxer represents the collection of all myns:Dog's
of a certain breed.  

Your version is better in the case that you don't think that it is important
- or perhaps don't believe - that all Boxer's are Dogs.  myns:Boxer and
myns:Dog are just two nodes in a graph that is connected by an edge that
happens to have the name HasChild.  

-Timothy


On 03/16/2012 06:07 PM, Jim Tivy wrote: 

Hi Timothy

 

Thanks for laying out the OWL2 formalisms.  I think OWL2 is a great data
modelling system.  

I only need to manipulate the data structure in a few ways and I am happy to
write those by hand.  I would like to discuss data modelling first, then
discuss reasoning (or rather agree not to discuss reasoning as right now
reasoning does not seem interesting). 

 

What I want to do is represent a Thesaurus which is a common well defined
structure that is described many places including here:
http://www.willpowerinfo.co.uk/thesprin.htm

 

In English (not in OWL2) I think of it this way:

There is a class of objects called Terms, some of which are in a hierarchy
some of which are not.  Each Term needs to have the following properties:

-        Scope Node

-        Broad Term

-        Narrow Term

-        Related Terms

 

My thought is to model this in OWL2 (excuse my paraphrase of OWL FL) as:

 

Declare Class Term

Declare Property(ScopeNode)

Declare Property(HasChild)  // to subsume BroadTerm and NarrowTerm are 

Declare Property(RelatedTerm)

PropertyDomain(ScopeNode,Term)

.

 

 

Individual(myns:Dog)

InClass(myns:Dog,Term)

ObjectPropertyAssertion(myns:HasChild,myns:Boxer,myns:Dog)

 

And so on.

 

Is that enough information?

 

Jim

 

 

 

 

 

 

From: protege-discussion-bounces at lists.stanford.edu
[mailto:protege-discussion-bounces at lists.stanford.edu] On Behalf Of Timothy
Redmond
Sent: March-16-12 5:13 PM
To: protege-discussion at lists.stanford.edu
Subject: Re: [protege-discussion] OWL2 Classes

 

On 3/16/12 1:22 PM, Jim Tivy wrote: 

Hi Folks

 

I am looking to implement a Thesaurus using the OWL2 model.  It seems the
recommended OWL2 modelling is to use a class for each term..  When I look at
class, however, it seems that it is very weak because the mechanism for
attaching properties to classes is weak.


Actually I think that the OWL 2 formalism is very expressive.  The thing
that you have to figure out is exactly what you mean by "attaching
properties to a class".   So if you have a class, A, a class B and a
property p you can say

*	all individuals in the class A must have a p-property value:

A SubClassOf p some Thing

*	all individuals in the class A must have a p-property value that is
in the class B:

A SubClassOf p some B

*	if some individual, i, has a p-property value then the individual i
must be an element of the class A:

p domain A


This is only just barely scratching the surface.  So tell us what you are
trying to express and we can start thinking about whether OWL 2 can express
it.

 

I think I am better served to have one class called "Terms" or "Concepts"
whose individuals express the Thesaurus.  In that way I can constrain
properties and reason about these individuals more naturally.


It may be that this is true but it seems very unlikely to me.  My sense is
that if you don't have a rich class structure then you are not going to have
much to reason about with the individuals.





 

I realize Class==Concept in OWL2, however I think that since Class itself is
not an individual that it is too weak.  What ever happened to the notion of
the Class Class.


What is the "Class Class"?  If you are thinking of meta-modeling, then my
reaction is that I think that realistic meta-modeling is probably often
quite difficult to get right.  But in any case, the starting point is to
figure out what you are trying to say.  Then we can figure out what language
capabilities you need to express your concept.

-Timothy






 

Jim

 

Jim Tivy - CTO, Bluestream

Skype: jimt.vanc

 







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