Re: [ontolog-forum] Just What Is an Ontology, Anyway?

To:	"'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From:	"Matthew West" <dr.matthew.west@xxxxxxxxx>
Date:	Fri, 30 Oct 2009 08:35:09 -0000
Message-id:	<4aeaa550.0a1ad00a.54a7.ffffd176@xxxxxxxxxxxxx>

Dear Rich,

Copied from below:

But then how do we account for the diverse viewpoints going into the system from multiple users? We all agree that each user has a unique ontology of her personal world. We know that subjectivity gets squeezed into the tightest databases with the strictest controls.

MW: You can’t. And in fact the problem really is just how do you impose sufficiently strict controls such that the range of meaning is sufficiently small that sufficiently accurate communication is possible.

You must. As John Sowa is fond of saying, people play language games.

MW: But computers don’t.

Those games are more complicated than we can decipher from signs alone. So one enterprise level purpose of each subjective personal ontology is to “correct” the personal viewpoint, projecting it back into the enterprise ontology.

MW: This is essentially the process of agreeing the enterprise ontology, or aligning with it.

But note that if you project the disjunction of all personal ontologies to make up the enterprise ontology, you have to match common items shared among personal ontologies.

MW: I don’t know anyone who would do it like that. Much more likely is that a few people determine the enterprise ontology, and then others are left with aligning their own viewpoint with it.

For example, probably most or all normal English speakers think of fluids in one way, solids in another and gases in a third. The English language reflects the way we talk about the things belonging to these different classes.

MW: One has to be very careful about this. Language includes lots of old ways of thinking about things that are not accurate. Ontology is about modeling how things are in the world, not how we talk about them.

So there is clearly a linguistic common ontology of objects and classes that constitutes everyday usage.

MW: No there is not, because with everyday language you can express any of the ontologies you might find. Words have such a variety of usages, that it can be difficult to accurately determine the meaning of words out o f context, and sometimes even in context.

That can be part of the enterprise ontology. But its part of EVERY language competent ontology.

MW: I’ve no idea what that might be. As I said above, ontology is about the things in the world, not how we talk about them.

So the enterprise ontology also includes things specific to the objects about which that enterprise is concerned.

Leading to the conclusion that the enterprise ontology will have to be multilayered, scalloped like a 50’s hot rod into component ontologies for each viewpoint and each group of viewpoints.

MW: Well yes you can do that (maybe), but at prohibitive expense because of the interfaces between vewpoints, so I doubt if anyone will. This is back to why a meeting of a French, Italian, German and Spanish people will conduct business in English.

Regards

Matthew West

Information Junction

Tel: +44 560 302 3685

Mobile: +44 750 3385279

matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx

http://www.informationjunction.co.uk/

http://www.matthew-west.org.uk/

This email originates from Information Junction Ltd. Registered in England and Wales No. 6632177.

Registered office: 2 Brookside, Meadow Way, Letchworth Garden City, Hertfordshire, SG6 3JE.

JMHO,

-Rich

Sincerely,

Rich Cooper

EnglishLogicKernel.com

Rich AT EnglishLogicKernel DOT com

From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Matthew West
Sent: Thursday, October 29, 2009 12:35 AM
To: '[ontolog-forum] '
Subject: Re: [ontolog-forum] Just What Is an Ontology, Anyway?

Dear Rich,

Looks like I missed something here.

So it looks like the consensus among those in this discussion is:

An ontology is a collection of

classes, each with possibly unique property values;

a few constant instances (e.g., equilateral triangle = special instance of generalized triangle, etc);

I’m not sure that I would see equilateral triangle as an instance. Surely there is more than one of them? On the other hand it could be a subtype of generalized triangle (some triangles are equilateral).

On the other hand there are plenty of individuals I might want in my ontology. If I want to define a class of “Ford Motor Car” in my ontology then it is useful to be able to have the individual “Ford Motor Company” in my ontology so that I can make the restriction class.

and

logical relationships among the classes and instances.

And nothing else. If that satisfies everyone, then any operational system would require more than just an ontology. It would also require that information nobody seems to want to call ontological, like the specific employees in the employee table.

If we accept this definition among the group of us, an ontology with a database to back it would be about the simplest semantic system I can imagine being useful. The database would store the instance data beyond the ontology, but the ontology would define the classes, properties and relationships among the entities.

MW: It will probably replicate much of the ontology too. It might be better to think of the ontology as an abstraction of the database, with some rules added, so that you can e.g. check the consistency of the database.

So how do we account for personal ontologies in a semantic system?

MW: The alternative is to document all the individual ontologies and map between them. This is horrendously expensive, so a much cheaper alternative is to sit down and agree to use one in a particular way, which may not be the way that any of the individuals actually sees things, but at least is clear. This is at least analogous to the situation you find when an Italian, and Frenchman, a German and a Spaniard have a business meeting. They speak English, rather than each have 3 translators.

So I suggest we return to the real world.