W3C home > Mailing lists > Public > public-owl-dev@w3.org > October to December 2010

Re: class and inviduals

From: Aldo Gangemi <aldo.gangemi@cnr.it>
Date: Mon, 15 Nov 2010 23:50:43 +0100
Cc: Aldo Gangemi <aldo.gangemi@cnr.it>, public-owl-dev@w3.org
Message-Id: <50D34D84-A1A4-4090-84AF-FC4E96FE5245@cnr.it>
To: Marcel Ferrante <marcelf@gmail.com>
Hi Marcel, this is a typical modelling issue. The solution is to treat terms alternatively as classes or individuals according to the requirement (or conceptualization) you have. 

In case you want to talk of Ferrari as a company, and your requirement is e.g. to ask about the foundation date of a company, Ferrari should be an individual; if you want to talk about Ferrari as a class of all concrete cars produced by Ferrari-the-company, you probably want to model Ferrari as a class.

In case of strong ambiguity, e.g. with maximally specified car models such as "Ferrari 365 GT/4 BB" (either a model or a concrete example of that model), OWL2 is very good at modelling the ambiguity by means of the so-called "punning" mechanism: the same term holds two different interpretations.

Good luck

On 15 Nov 2010, at 22:59, Marcel Ferrante wrote:

> Hi,
> Sometimes, when we define class and individual to students, appears some doubts.
> For example:
> In the owl reference (http://www.w3.org/TR/owl-ref/) class is defined as "abstraction mechanism for grouping resources with similar characteristics"
> or class define a set of individuals with same characteristics in common.
> A good exemple is car (class) and ferrari enzo (individual).
> But there is many cars that are ferrari enzo, so ferrari enzo could be a class and Jonh's ferrari enzo an individual.
> So ferrari enzo could be a class and an invidividual in the same ontology ? Or ferrari enzo could be a subclass of car,
> but its diferent than a tradiconal subclass like sport car.
> Is there a more clear definition of class and individual ?
> Thanks in advance,
> Marcel
> -- 
> Marcel Ferrante Silva
> +55 31 8851-9069 3785-9069
> skype: marcelferrante
> gtalk: marcelf@gmail.com


Aldo Gangemi
Senior Researcher
Semantic Technology Lab (STLab)
Institute for Cognitive Science and Technology,
National Research Council (ISTC-CNR) 
Via Nomentana 56, 00161, Roma, Italy 
Tel: +390644161535
Fax: +390644161513
skype aldogangemi
okkam ID: http://www.okkam.org/entity/ok200707031186131660596
Received on Monday, 15 November 2010 22:51:22 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:58:19 UTC