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Re: [ontolog-forum] Time representation

To: "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Pat Hayes <phayes@xxxxxxx>
Date: Fri, 25 Jan 2008 10:32:56 -0600
Message-id: <p06230907c3bfb5fd4ccd@[]>
At 11:43 AM +0000 1/25/08, <matthew.west@xxxxxxxxx> wrote:
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Dear Pat,
At 8:33 PM +0000 1/24/08, Chris Partridge wrote:
I have cut out some irrelevant stuff.

>>I think this is where ontology (as a picture of reality comes
>I don't follow. Why would it come in here more than in designing
>software? Surely you aren't thinking of ontologies as new scientific
>theories (are you??)

There is a long tradition of regarding computer systems as theories.

As *scientific* theories? 
MW: No. It was you that introduced the word "scientific".

The examples given by Chris to illustrate his intended meaning were all scientific theories. The word 'fruitful' is used in philosophy of science, to refer to scientific theories. Chris seems to have hijacked it to mean something else.  Apparently, there is simply a muddle here about what a 'theory' is. If we don't put a stop to this, we will soon be debating what "is" means.

I will
give you the quotes if you wish.

Jonathon Lowe (a philosopher I recall you meeting) has a technical
definition of ontology as "the set of things whose existence is acknowledged
by a particular theory or system of thought." (E. J. Lowe, The Oxford
Companion to Philosophy)

He is clearly using the word in its philosophical sense, not its IT sense. Nobody in this forum is doing philosophical ontology. 
MW: How would you distiguish his use of the word "theory" from the meaning that you would ascribe to it in a computing sense?

He is defining "ontology" in its philosophical sense. I have no idea what he means by 'theory', but 'system of thought' sounds pretty ambitious for an IT concept.

Taking these two points together, one can regards a computer system's
ontology as (roughly) "the set of things whose existence is acknowledged by
a particular computer system"

Im not sure what that means, but its certainly not ontology as in 'ontology engineering'. 
MW: In what way is it different?

We here refer to ontologies as computational artifacts. We engineer them, and invent formalisms to write them in. For us, the ontology itself describes things that exist. For Lowe, the ontology is the things that are described, not their description. Also for Lowe, there is no such thing as a formalization of an ontology (or if there is, it is incidental, a mere tool to clarify some point), whereas for us, an 'unformalized ontology' is merely a preliminary sketch. For Lowe, the notion of 'ontology engineering' would be incoherent, meaningless. Also, if anyone doubts that the two fields are different, let them just try reading some actual philosophical ontology (see for example the article on ontology in the Stanford encyclopedia of philosophy.)

In what sense is the set of things that a system will let you hold information about not its ontology? If it is not its ontology, what is it?

I have no idea what we are talking about. What is a "system"? What is "information"? At this level of generality any coherent meaning evaporates, and we are just tossing word-salad at one another.

>>When we reflected upon this, what we realised is that we had tried (and
>>succeeded to an extent) in capturing the main features of corporate
>>- and that the new (unrecognised) situations were just (very) unfamiliar
>>combinations of familiar features.
>You were lucky!

The issue for us was that this became a regular feature, so it seemed to be
more than luck.

I meant, you were lucky that you only had to go around the knowledge extraction loop once. 
MW: Perhaps, but it might also be skill in the knowledge extraction process that enables the "fruitfulness" that Chris refers to.

If so, it would be far more useful for Chris to tell us how this skill is achieved, because that is truly remarkable. I work with people who do this for a living, and Ive never heard any of them claim to be able to get useful KE done without some iteration, except by a rare stroke of very good luck.

>That seems on the face of it to be self-contradictory. Isnt it pretty
>much the definition of 'unforseen' that one cannot plan for it ahead
>of time, since it is invisible?

I think there is a difference between saying that we can foresee that we are
going to do USD/GBP currency exchanges - and how we plan for that in a
And saying that the financial markets are volatile, and new instruments are
going to arise (whose details we do not know) - and how we plan for that. At
some level, we are saying that we cannot foresee what is going to happen.

Right. So how is it possible to plan for something that you cannot forsee, other than in a general sense trying to stay alert? 
 MW: After your response to Pat C advising him to favour an ontology of time that did not make a commitment to a continuous or granular view of time, exactly the kind of fruitfuness in design Chris and I are advocating, I am surprised that you would say that.

Thats got nothing to do with 'unforseen'. I know exactly what will break when either of these is put into a core time ontology.

Fruitfulness in design, for me, has a lot to do with not closing off possibilities unnecessarily.

Why did you or Chris not just say THAT, then, rather than introducing this new, wooly, under-defined vague general notion? Already in this forum I have read posts which are taking the understanding of the term in diametrically opposite directions (don't include too much stuff/include everything possible; make it general/don't make it too general, bottom-up/top-down. Im waiting to see if we get middle-out; silly-mid-off can only be around the corner.)

 This is not so much a matter of forseeing future requirements, as designing, in a way that allows what is possible.
>>One way of doing this is to try and make
>>the design reflect what is actually happening reasonably accurately
>?? Surely that is exactly what one should not do, in order to be able
>to handle unforseen situations. That strategy will lock in the way
>things are at the time the system is designed, not the way that
>things might become later.
>>  - one
>>way of testing this is to see how fruitful the design is.
>How does one set out to do that? This sounds about as clear as
>testing a design for 'elegance' or some other unmeasurable subjective

I do not understand. The test is reasonably simple and has clear results. If
you want details you can read the book. What is immeasurable or subjective
about it?

I need to read the book, obviously, but I suspect we are at cross purposes. I cannot even imagine what would be a simple test of success at solving an unforseen problem. Unforseen by who, when? Suppose it turns out to be able to do something unforseen, but the designer then tells you they had in fact forseen that and planned for it. Who is to contradict them? 
MW: Yes, I think you  are at cross purposes. I suspect that one of the problems here is that you would take what I would call fruitful design as obvious, but it is not so frequently practised. A good test of fruitful design is that it does not make any statements that are not true under all circumstances

Hmm. Might be better called Tautologous Design, from this description :-)

(in any context to bring together two threads). It is precisly this that makes a piece of ontology portable, reusable, and hence fruitful.

But in any case, why has this got anything much to do with ontology design? Do you feel that ontologies should be designed for unforseen things more than other artifacts? 
MW: I think you are getting too hung up on this unforseen thing. It is not the main point

It was the *defining* point in Chris' presentation.

You know, with the best will in the world, I really DO NOT WANT TO KNOW what you and Chris take 'fruitful' to mean. I know what Keats meant, and thats enough for me. I want us to talk about ontology engineering. If you think some piece of management NewSpeak is of real utility for our goals, please bring the matter down to earth and tell us more concretely what you think we should be doing and/or not doing (like below). But I just don't have time to put myself through another of these BS tortures. Ive been to excruciating courses on Total Quality Management, Ive read more books than I care to remember about how to do better IT engineering by following some new slogan or new Method. (Perhaps its because managers have so little to actually do, that they write all this stuff?)

, reusability, flexibility, and extensibility are the results of fruitfulness, whether or not you can forsee all the consequences that this might bring. The kind of behaviours that lead to this are not placing constraints at a higher level in the ontology than they truly reside

Well, that's a pretty good rule, I agree. Are there any others?

, just because other parts of a larger ontology are not part of the requirements this time - one of John Sowa's hobby horses, and another way of saying what I said above, about making statements that are true in all circumstances.


Matthew West
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