[Sigia-l] Ontologies vs. DM-Even Longer-Sorry!

[Nuno Lopes]

Hi Lisa,

>I probably wouldn't create classes of individuals who
>are defined strictly on a relationship. So, "parent"
>would be a relationship between two individuals and
>"employee" would be the relationship between an
>individual and an organization. ("employer" could be
>defined as the inverse, but it's not necessary).

I see. But that fact is that you admit (is how interpret the word
"probably" in the beginning of the sentence) that [Employee] and
[Employer] can be in fact entities (ask a lawyer:). If they are, then
they should be a class that is defined by the relationship. 

To turn the problem more explicit the question is - Where would you put
the concept of Employment Contract? Should it be in the relationship?
Should it be it be in the [Person], in the [Organization]? If you admit
that the concept of Employee can be in fact an mapped into a class
[Employee] then should it be here? Should it be in the class [Employeer]
by the same reason?

In OOA and using UML as a language we could:

	 Develops Role             Employment

[Person] --------- [Employee] --------.-------- [Employer] ...
   |                                  |
   | Develops Role                    |
   |	                            [Contract]
[Parent] .....


The organization sees an Person as an Employee (is this a fact of a
person?). The Person may sees the organization who as an Employment
Contract with as an Employer.

This kind of modeling allows new roles to be developed by the person
without changing the nature of being a person (as happens in real life).
The same thing can be said by the organization.

With Ontologies (Syc?)

[Person] ---- [Contract] ------ [Employer]
    |                                |
    ----------------------------------
      	Employment (transitive)

I honestly don't like this.

In categories (OOA):

So we have:

Human
	Person

Person Role
	Employee
	Parent

Organization
	Government
	Corporation

Organization Roles
	Employer


>What is in a name? Actually there is another "lisa
>colvin"! She is an IA in Los Angeles. I have been
>working mostly as an ontologist in the SF Bay Area.
>This is very confusing. I found out when we both
>applied for the same job! Pretty funny.  So,
>unfortunately, I can't answer any of your other
>questions.

I guess I go confused by some other post in another list. Sorry.


Best regards,

Nuno Lopes