W3C home > Mailing lists > Public > www-rdf-logic@w3.org > March 2003

Re: Treating a class as both an individual and a class?

From: Roger L. Costello <costello@mitre.org>
Date: Mon, 10 Mar 2003 07:42:57 -0500
Message-ID: <3E6C8851.4DA873B2@mitre.org>
To: www-rdf-logic@w3.org
CC: "Costello,Roger L." <costello@mitre.org>

"Peter F. Patel-Schneider" wrote:
> 
> > Suppose that I want to use this River class as an individual, as 
> > shown here:
> >
> >     <Country rdf:ID="China">
> >         <hasFeature rdf:resource="http://geodesy.org#River"/>
> >     </Country>
> >
> > Note that the property "hasFeature" has as its value the class 
> > River. Thus, the River class is being treated as an "individual".
> 
> Hmm.  I don't think that this is correct modelling.  You are *not* 
> saying anything related to whether China has a river in it. 

What I was trying to express in this example is that the country China
possesses the geographic feature "River".  I agree that it is a poor
example.  Let me give another example. 

In this example, I would like to express some of the major features of
my hometown of Davenport, Iowa:

    <City rdf:ID="Davenport">
        <hasFeature rdf:resource="http://geodesy.org#River"/>
        <hasFeature rdf:resource="http://geodesy.org#Interstate"/>
        <hasFeature rdf:resource="http://geodesy.org#Airport"/>
    </City>

Is this good modelling?  Does it effectively model the major features of
my hometown?  Note that River, Interstate, and Airport are "classes". 
Thus, in this example I am treating these classes as individuals.

> However, you do need to remember that metaclasses may not give you all 
> that you might think that they are giving you.

A very interesting statement Peter.  Would you elaborate please?  /Roger
Received on Monday, 10 March 2003 07:43:39 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:52:43 GMT