SUO: Questions-comments about SUMO116.pprj: Concepts and Types
Dear SUOntists,
as this is my first message to the list, I should probably introduce
meself. At this purpose there is a short description of my research
project at the end of this e-mail. For any further relevant information
on my research, please see the paper on causality which was presented at
the SUO workshop (Lehmann & Breuker 2001).
Here I would like to go immediately to the point, by putting a
(structured) question to whom in the list might be interested to provide
an answer, or at least a replay. I need to solve some doubts of mine,
which might have some relations to SUMO. In order to avoid unnecessary
boredom to the reader, I invert the logical order of paragraphs (i.e.,
first the questions (4) and then the premises to the question (1, 2, 3)).
Looking forward to some feedback,
Jos.
4. Questions: I'm really positively impressed by the quantity of
information in SUMO (-116.pprj). It seems to me there is a problem,
though, in the organization of such information. I think such luck of
organization is *also* due to an abuse of the subclass relation, which
is used for representing both subconcepts and subtypes. (For instance: I
would consider a Region to be a type of the class-concept object rather
than a subconcept of it - i.e., a region is a subconcept of the
class-concept object which *only* inherits *a part* of the slots
comprised by the class-concept object, not all of them! Why would a
region need, for instance, such a slot as "exploits"?). So, I wonder:
a. Is there any technical reason for not distinguishing between
concepts and their types, and "squeezing them all" in the ambiguous
subclass relation?
b. If not, wouldn't it be possible to make such distinction by means
of an incremental inheritance of slots by the types of an object?
c. How would this incrementality be expressed in Protege, Ontolingua
or KIF?
1. Premise: I'm working at the implemantation in Protege 1.6.1 of a
revised version of the ideas presented in (Lehmann & Breuker 2001).
After a month of stuggeling with Ontoligua, I decided to pass to
Protege. I thought that this choice would in the end make more difficult
to produce a KIF version of my ontology and therefore complicate
communication with anything produced by SUO. To my pleasent surprise,
though, two days after I started working with Protege, Adam posted
SUMO116.pprj to the Protege-users list.
2. Premise: A fundamental distinction I "cherish" in my definition of
causal relations, is the distiction between Concept and Type.
a. A concept is just a set of attributions (in Guarino's terminology).
b. A type is a concept plus a priority, i.e. an order between the
attributions, plus a fixed range of the attributes, i.e. the values of
the attribution (in Guarino's terminology).
3. Premise: Just like in SUMO, the fundamental concepts of my ontology
of causal relations are the notions of object and process. By following
what explained in 2, I would proceed as follows in defining such two
concepts and their types:
a. Define a series of attribution (as slots in Protege). Example:
:Location, :Mass. Ranging on attributes (classes in Protege) Location,
Mass
b. Define a class (Object) comprising such slots (:Location, :Mass).
Example:
Object:
:Location, :Mass
c. Define a relation (a facet in Protege) that fixes the ontological Priority
among slots. Example: Priority(:Location) = 1, Priority(:Mass) = 2. (Done)
d. Define Type of Object (sub-class of Object in Protege), according
to the fixed Priority and to ranges of the instances of the classes
underlying the (prioritized) slots. Example:
ObjectType1 (Universal): :Location = Any;
ObjectType1.1 (Concentrated): :Location = Any, :Mass > 0; ObjectType1.2
(Concentrated): :Location = Any, :Mass = 0.
The result would look as follows (A tree, I hope...;*):
Object: (Concept)
:Location,
:Mass
|
ObjectType1 (Universal Object):
:Location = Any.
/\
ObjectType1.1 (Concentrated): ObjectType1.2 (Distributed):
:Location = Any, :Location = Any
:Mass > 0 :Mass = 0
======================================================
Background of my reasearch
I am currently working on the development of
an ontology of concepts (i.e. classes) for reasoning about the causal
relations that hold in the description of a legal case. The general aim
of my project is to come up with a meta-model of the essential data that
are necessary (and sufficient) for (automatically) determining chains of
causation (and legal responsibility) in a case. I intend to use Protege
2000 for storing my ontology, which in its natural language form
consists of approx. 40 definitions.
======================================================
--
Jos Lehmann
Research assistant and Ph.D. candidate
Department of Computer Science and Law
Faculty of Law
University of Amsterdam
jos@lri.jur.uva.nl