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I read Deborah's paper, Leo's presentation and other materials on ontology
spectrum that were mentioned on this list. I found it's a nice way to view how
knowledge representation has been evolved. If I understand correctly, the
ontology spectrum view implies the term "ontology" is used almost as
the replacement for "knowledge representation".
In
addition to the broad view from "ontology spectrum", I'm interested
in looking deeply in the more strictly defined ontology space, where an
ontology represents a specific aspect of the real world using class objects
that can be expressed in clearly defined languages (like RDF, OWL). By focusing
on this strict ontology space, I hope we may be able to come up with some sort
of framework that will help people develop more reusable ontologies (in RDF/OWL
or newer languages). A classification scheme may be one component of this
framework. There are probably lots of work done in this direction already
that I don't know about. Please provide pointers to any relevant work if you
know any. Coming from object-oriented software development background, my sense
is that we should be able to learn a lot from reusable software design. When an
ontology is coded in a language, it's conceptually possible to map the ontology
to a layer of ontologies designed with different granularity. And these
different layers of ontologies should be about to talk to each other in an
integrated application.
Again, using examples of real ontologies
to further understand the problem of reusability is neccessary. In my previous
post, I tried to use my own examples to illustrate the problem. Hope more
people will bring their examples into the discussion as well. AJ
--
AJ Chen, PhD
http://www.web2express.org
"Open Data on Semantic Web"
Quoting "Deborah L. McGuinness" <dlm@xxxxxxxxxxxxxxxx>:
> hi - i am catching up on email so sorry to come in mid stream. i have
> not gone back through the whole thread but figured i would chime in now
> while the discussion is on a spectrum.
> i have gotten a LOT of leverage out of the notion of an ontology
spectrum.
>
> In 1999 a number of us were on an ontology panel at aaai. as homework
> for the panel, we had a pre-meeting about what each of us were willing
> to call ontologies. It might be useful to explain my perspective when i
> participated (which actually still reflects my perspective now on the
> topic).
> this was just after i had done a fairly comprehensive consulting project
> looking at "naturally occurring" things that might be
considered
> ontologies as a LARGE crawl to obtain starting points for a very
> comprehensive ontology.
> In that effort i looked in excruciating detail at a number of mostly
> taxonomies like yahoo shopping, lycos, amazon, as well as a number of
> subject specific taxonomies and things i consider light weight
> ontologies - class hierarchies where the classes have a small number of
> properties, sometimes with value restrictions. i was working in the
> context of a startup with a very broad user base so somewhat by
> necessity, i needed to consider what the general public might consider
> an ontology and how a broad set of people might use it.
> i also was in the midst of a large ontology-driven project - hpkb -
> where my team had to answer questions using 80 kbs as input. the
> knowledge bases were all essentially kif statements (or they had been
> translated into kif) and they were generated by people at least
> reasonably trained in kr and the kbs had a lot of structure. so i had
> been doing A LOT of ontology and knowledge base merging at that time in
> my life - an it was driven somewhat by two fairly different desires and
> needs for ontologies - 1 heavy weight theorem proving to generate
> answers and 2 very light weight ontology-enhanced search. (i still find
> myself driven by these 2 needs on a very regular basis).
>
> the ai panel members (welty, gruninger, uschold, lehman, and myself)
> came up with an ontology spectrum that i have grown to like quite a bit
> - but of course that is because it reflects a lot of my personal
> experiences with structured declarative knowledge representations from
> extremely lightly structured things to very principled, detailed
> structured artifacts. the belief i came to then and the one i still
> stand by now is that we are more likely to have structured knowledge get
> used in applications if we work with the notion of a spectrum and help
> people move along it as their needs and education permits.
>
> I gave a talk in early 2000 about the pull i was experiencing for
> ontologies at a dagstuhl meeting and used the spectrum as an organizer.
> I wrote a paper describing my view of each of the points on that
> spectrum along with some examples of my experiences in each of those
> points. i wrote the paper in 2000 with a small update in 2001 but the
> actual published version of it came out in a book from that even MUCh
> later - actually 2003.
> an online "preprint" version is up at:
> http://www.ksl.stanford.edu/people/dlm/papers/ontologies-come-of-age-mit-press-(with-citation).htm
>
> one reason i bring up that paper is that i still find that a lot of
> people tell me they get value out of that paper i think for 2 reasons -
> 1. the simple spectrum (yes - i think one dimension of expressiveness is
> really too limiting... but it is convenient pedagogically.)
> 2 the examples of each point on the spectrum.
>
> i would be happy to co-author a next generation of something like that
> paper.... and in fact, i have been asked for such a paper on a regular
> basis with more examples and more current references.
>
> deborah
>
> Obrst, Leo J. wrote:
>> Charles,
>> I agree with you. A number of us through the years have come up with
>> similar ontology continuums or spectrums. I prefer my Ontology
>> Spectrum*, but that's natural, I guess. It was developed over time
to
>> act as an educational aid. I found that many folks understood
notions
>> such as taxonomies, database schemas, UML models, but they didn't
know
>> how these related to the new kid on the block, ontologies. Was a
>> thesaurus an ontology? No. Was a UML model: no, not yet. And term
vs.
>> concept (placeholder for real world referent) is a crucial
>> distinction. The former is a word/phrase (string, utterance) that
>> indexes the latter, which is a representation of the meaning of that
>> term (at least approximately). The important point is that these
>> concepts/placeholders are meant to stand in for real world
referents,
>> since ontology is about the things of the world. I also attach a
newer
>> slide that tries to show those distinctions, along with their
typical
>> use cases: OntologySpectrumApplication-Obrst06.jpg.
>> Thanks,
>> Leo
>> *If you look at the current Wikipedia article on the subject, it's
not
>> completely accurate: http://en.wikipedia.org/wiki/Semantic_spectrum.
I
>> independently developed the Ontology Spectrum in Fall, 1999, and it
>> really represents one dimension, though it is depicted diagonally
(for
>> increased space) as though it were two dimensional: the one
dimension
>> is in terms of expressivity of the model. Also the 4 way stations of
>> taxonomy, thesaurus, conceptual model, and logical theory are
semantic
>> models; that is why I don't include glossaries, term lists, etc.,
>> directly -- they are not models but are human language lists and
>> definitions. Mike Uschold, Mike Gruninger, and Chris Welty and I
have
>> talked about this topic of the co-invention of the semantic/ontology
>> spectrum for quite some time. Personally, I prefer my Ontology
>> Spectrum because I overlay onto the specific models additional
>> information, such as the kind of parent-child relation, related
>> database and modeling languages, and logic information. But all of
>> these ontology spectrum/semantic continuums are sound: they
represent
>> the best distillations of solid generalizations especially good for
>> educational purposes.You are probably referring to the presentations
I
>> gave at Ontolog last Jan 19/26 2006: "*What is an ontology? - A
>> Briefing on the Range of Semantic Models*",
>> http://ontolog.cim3.net/cgi-bin/wiki.pl?ConferenceCall_2006_01_12.
>> _____________________________________________
>> Dr. Leo Obrst The MITRE Corporation, Information Semantics
>> lobrst@xxxxxxxxx Center for Innovative Computing & Informatics
>> Voice: 703-983-6770 7515 Colshire Drive, M/S H305
>> Fax: 703-983-1379 McLean, VA 22102-7508, USA
>>
>>
------------------------------------------------------------------------
>> *From:* ontology-summit-bounces@xxxxxxxxxxxxxxxx
>> [mailto:ontology-summit-bounces@xxxxxxxxxxxxxxxx] *On Behalf Of
>> *Charles D Turnitsa
>> *Sent:* Monday, January 22, 2007 1:39 PM
>> *To:* Ontology Summit 2007 Forum
>> *Subject:* Re: [ontology-summit] Defining "ontology"
>>
>> One of the big schisms in types of ontology that I see is a
>> difference in an ontological representation (model) that is
>> intended to organize knowledge at the level of terms, and a
model
>> that is intended to organize knowledge at the level of meaning.
>>
>> If you look at the Ontology Spectrum that was presented to the
>> Ontolog group last year by Dr. Leo Obrst, you see a progression
of
>> ontology representation techniques, from controlled vocabularies
>> and simple data models, up through thesauri, taxonomy
techniques,
>> up to axiomatized systems and logic based models (and beyond).
One
>> of the big shifts I have seen is the difference in emphasis of
>> lower level models (thesauri and controlled vocabularies, for
>> instance) on terms, and the attempt of upper level models (axiom
>> based systems, logic models) on definitions. For different
>> communities, differently focused applications, both appear
equally
>> useful, but they are very different.
>>
>> From all of this, possibly an axis of differentation for
>> ontologies can exist to show the focus of what the ontology is
>> defining, and the depth of it's intended use.
>>
>> Chuck
>>
>> Charles Turnitsa
>> Project Scientist
>> Virginia Modeling, Analysis & Simulation Center
>> Old Dominion University Research Foundation
>> 7000 College Drive
>> Suffolk, Virginia 23435
>> (757) 638-6315 (voice)
>> (757) 686-6214 (fax)
>> cturnits@xxxxxxx <mailto:cturnits@xxxxxxx>
>>
>> -----ontology-summit-bounces@xxxxxxxxxxxxxxxx wrote: -----
>>
>> To: Ontology Summit 2007 Forum
<ontology-summit@xxxxxxxxxxxxxxxx>
>> From: Patrick Durusau <patrick@xxxxxxxxxxx>
>> Sent by: ontology-summit-bounces@xxxxxxxxxxxxxxxx
>> Date: 19/01/2007 08:53AM
>> Subject: [ontology-summit] Defining "ontology"
>>
>> Greetings,
>>
>> I am concerned with the suggestions that it is possible to
>> create a
>> continuum along which to organize what are known as
>> "ontologies" in one
>> or more circles.
>>
>> At least unless we are willing to concede that the creation
of
>> such a
>> continuum is itself an imposition of assumptions from an
>> undisclosed
>> ontology.
>>
>> I am sure there are those who would say that folksonomies
are
>> "missing"
>> features that are present in "formal" ontologies.
Perhaps, but
>> folksonomies predate "formal" ontologies by several
millenia
>> and have
>> proven robust enough for many purposes. If the goal is to
>> represent the
>> opinions of the many rather than the few, perhaps it is
"formal"
>> ontologies that "missing" features.
>>
>> I am not taking a position one way or the other. But, I do
>> think it is
>> important to realize that any attempt to construct a
continuum
>> is with
>> an unstated choice of a winner before the the continuum is
>> populated.
>>
>> Hope everyone is looking forward to a great weekend!
>>
>> Patrick
>>
>> --
>> Patrick Durusau
>> Patrick@xxxxxxxxxxx
>> Chair, V1 - Text Processing: Office and Publishing Systems
>> Interface
>> Co-Editor, ISO 13250, Topic Maps -- Reference Model
>> Member, Text Encoding Initiative Board of Directors,
2003-2005
>>
>> Topic Maps: Human, not artificial, intelligence at work!
>>
>>
>>
>>
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>>
>>
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>>
>>
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>
>
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