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Charles,
Some comments below. But also see my reponse to AJ
Chen.
Thanks,
Leo
_____________________________________________
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
Leo, If I can offer up a couple of observations related to
your "underlying methodology" comments, I can think of two aspects of an
ontology that might prove useful to an effort at categorizing "types" of an
ontology. The first relates to the perspective, or goals, of the
designer of the ontology. It is apparent that an ontology of industrial
compounds would be quite different if it were developed for a chemist than if
it were developed for a wholesale supply company. Perhaps there are a
few characteristics that can generally define the perspective of an
ontological representation - such as "composition", or "function". It
might be that this is too individual to capture in a "typing" of ontologies,
but it may be that in a few key ways, similar to whatever differences exist
for ontologies based more on objects or more on processes (with apologies to
4D-ists who see little difference between the two), it might prove
useful. [LEO:] You are correct. At VerticalNet (a former B2B e-commerce
dot.com), we had exactly this kind of issue. A supply chain of
companies might include 1) raw chemical manufacturers, and 2) paint
manufacturers. (1) will focus more on the physical properties of the
chemicals, their purities, base stable states, etc. (2) will focus more on
functional properties such as light-reflectability, drying-time,
heat-resistance, etc. I think Pat Cassidy here and others have remarked before
that in general human artifacts will tend to have functional properties.
And when you consider the notion of what a human artifact is, it seems quite
reasonable, i.e., it is a teleological or at least agentive property, i.e., a
property incorporated into the design of an artifact to serve some
function or have some purpose. A hammer may or may not be a natural kind
(I don't think it is, unless you consider a tool a natural kind), but it
is an entity in the real world (a specific type of tool) that will
figure in someone's ontology, as are many human artifacts:
tanks, buildings, computers, money, software,
ontologies-qua-engineering-models, etc. The second
relates to whether an ontology is "descriptive" (describing the communications
that already exist within a domain, and the entities and relationships that
are supported within the existing modes of that communication), or
"prescriptive" (describing the domain in as objective a manner as possible,
given an objective set of referents, regardless of the ability of systems,
etc, to communicate at that granularity of understanding). The first of
these two seems to me to be the more practical of the two, while the second
seems to be the (potentially) more epistemologically accurate. [LEO:] Interesting
point. the upper ontology DOLCE (Descriptive Ontology for
Linguistic and Cognitive Engineering: http://www.loa-cnr.it/Ontologies.html.) explicitly
distinguishes descriptive vs. revisionist (i.e., more
alligned with prescriptive) ontologies. It's the tension between 2
interpretations of ontology, i.e., what are the notions significant to
humans or other agents (linguistic and cognitive) vs. what are the
underlying notions (independent of the conceptualizing
agents). Multiplicative vs. reductionist notions are also discussed
in the DOLCE paper (cf. pp. 11-12 of WonderWeb Deliverable 18, Claudio Masolo,
Stefano Borgo, Aldo Gangemi, Nicola Guarino, Alessandro Oltramari,
December 31, 2003.)
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
-----ontology-summit-bounces@xxxxxxxxxxxxxxxx wrote:
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To:
"Ontology Summit 2007 Forum"
<ontology-summit@xxxxxxxxxxxxxxxx>
From: "Obrst, Leo J."
<lobrst@xxxxxxxxx>
Sent by:
ontology-summit-bounces@xxxxxxxxxxxxxxxx
Date: 24/01/2007
03:34PM
Subject: Re: [ontology-summit] Defining "ontology"
Hi, Deborah, yes, I would be interested in such a
revised paper. In
fact, I think that this Ontology Summit effort is
focused on nearly
exactly that purpose, to describe the range of notions
that people
sometimes call "ontology" and perhaps "type" those notions
along a
multi-dimensional continuum/spectrum: type 1, type 2, etc. So
perhaps
the paper could be an outcome of this discussion group's effort.
One notion that is lacking in our discussion so far and lacking
even
from the informal-formal dimension is the "source" or
"underlying
methodology" of the "ontology" (I use quotes around these
because they
all probably need to be defined, perhaps as part of our
effort here).
So, for example, the informal-formal poles do not capture
how the
"ontology" is developed. One could characterize this notion
of
"methodology" as the "empirical/rationalist" or
"bottom-up/top-down"
perspective or predilection. Folksonomies, e.g.,
would probably be on
the empirical/bottom-up side; logical theories
(formal ontologies)
would be on the rationalist/top-down side.
And there are other such
dimensions.
Thanks,
Leo
_____________________________________________
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
-----Original Message-----
From:
ontology-summit-bounces@xxxxxxxxxxxxxxxx
[mailto:ontology-summit-bounces@xxxxxxxxxxxxxxxx]
On Behalf Of Deborah
L. McGuinness
Sent: Monday, January 22, 2007
10:27 PM
To: Ontology Summit 2007 Forum
Subject: Re: [ontology-summit]
Defining "ontology"
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-mi
t-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
>
>
-----------------------------------------------------------------------
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>
*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>
>
>
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>
> 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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