To: | edbark@xxxxxxxx, "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx> |
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Cc: | "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>, ontolog-forum-bounces@xxxxxxxxxxxxxxxx |
From: | jayanosy@xxxxxxxxxxxxxxxxxxx |
Date: | Thu, 3 Dec 2009 16:19:39 -0600 |
Message-id: | <OF27D7B60B.AAC9B125-ON86257681.007984D4-86257681.007AA641@xxxxxxxxxxxxxxxxxxx> |
Ed, Bill, My understanding is that instances in a domain identified by some symbol are asserted to be members of a specific Ontology concept, thus having potential property relationships to other individuals and their denotation symbols in other concepts in the Ontology. Whether these symbols denote real objects in a domain of discourse or states of affairs or situations is immaterial, the relationship between the symbol and something in the real or human conceptual world is entirely defined by humans. If the labels used for concept and properties in the ontology are from some domain of discourse by people, the common understanding from shared background knowledge may be more accurately understood by a subset of people who know that domain adn they may have a better chance of understanding the expressions of the ontology in the language used. Yet! the ontology has very specific meaning asociated with its structure of relationships and rules of inference, which is a very small subset of knowledge in a domain. When I read an ontology i always have to concentrate on what the ontology is saying rather, and be very careful not to add meaning not defined by the ontology. Is my understanding correct? Best Regards, John A. Yanosy Jr. Cell: +01-214-336-9875 PH: +01-972-705-1807 Email: JAYANOSY@xxxxxxxxxxxxxxxxxxx
Bill, I think we agree, but we are talking about two different topics. I wrote: >> It means exactly what it says and only what it says. >> Bill wrote: > Does not make sense without considering (at least a limited) social setting. The ontology means absolutely nothing if there is no human (or his/her software surrogate) to interpret it. "Meaning" is a human phenomenon - isn't it? > This is entirely correct. But, as I said, the intended audience for an ontology -- a software artifact that represents knowledge in a formal logic language -- is not primarily human. A human can read the ontology and assign all kinds of loads to the terms, but the reason why a human reads the ontology is only to determine whether it is suitable for use by his software in performing his target application. A reasoning engine, or another software tool, will only work with the formally specified elements according to the formal meaning of the formal language. The notion "meaning" for the software tooling is what inferences it can make, what derived forms it can produce, what decisions it will affect. And those will not be based on what the human thinks the ontology terms "mean". The human is judging whether the ontology is "practically consistent" with his intent. And he may be wrong in his initial judgement. He may get specific inferences he didn't expect. But that is exactly the same learning process that two humans go through in establishing effective communication. They think they have agreement on the concepts, terms and rules, until some outlier case demonstrates that they don't have quite the same concepts. The idea here is that what the software will do with the ontology concepts should be predictable (within the limits of competencies and implementation errors), but what humans will do with any exchange is not predictable, because we cannot really know exactly what meaning they took from the exchange. What makes the human interactions work is tolerance and fuzziness, but what makes the software work is the rigidity. We do not yet know how to make software that reads natural language text and behaves as predictably and as usefully as software that interprets formal ontologies. If your objective is to improve communication between humans, it is not clear that an ontology is better than a text corpus. That said, the strictures of a formal language force a discipline on the author of the ontology that may improve the communication over what that person would have written in natural language. And in fact, as some previous discussion on this exploder revealed, a lot of knowledge engineers have discovered that introducing formalism and graphical presentation of concepts often significantly improves the ability of a group of domain experts to achieve a reliable common terminology and understanding. It gets them past the sloppy text that passes for communication of concepts in their communities and the related presumption that unspecified properties and constraints are part of the shared understanding. You and I are probably in violent agreement. My long-standing point is that knowledge engineering is an engineering discipline; it is not a branch of philosophy or linguistics or cognitive science, and it is not primarily about communications among humans. It is about communicating between humans and software. The amazing thing about AI software is that it doesn't have any idea what domain it operates on, or what any of its manipulations actually "mean", but it produces valuable results. But then again, the same is true of Newton's calculus, and the IBM 704. (I am reminded of a presentation I heard about 30 years ago from a person from Shell Oil. He described an elaborate program for evaluating their software performance in various ways and making improvements in certain areas to reduce the total computational time. At the end, he said: "Taken together, this set of improvements (which must have cost several million dollars) has reduced our total computational load by 12%." And as the audience snickered, he followed that with: "Since the Shell research center has 9 5M$ computer systems, that saving is one entire computer system!" The meaning of a result is definitely context-dependent!) -Ed -- Edward J. Barkmeyer Email: edbark@xxxxxxxx National Institute of Standards & Technology Manufacturing Systems Integration Division 100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528 Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694 "The opinions expressed above do not reflect consensus of NIST, and have not been reviewed by any Government authority." _________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx Shared Files: http://ontolog.cim3.net/file/ Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx _________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx Shared Files: http://ontolog.cim3.net/file/ Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (01) |
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