Ian,
Good to hear from you, I have never had a reason to filter your posting.
Reasonable questions, and I will try to answer interspersed below. (01)
> In the thread that's been running, you indicate that you believe there
> are some common ontic primitives that can be shared across multiple
> ontologies -
> e.g. as a foundation. Do you have a clear idea of what these might be ?
> (some examples would really help my understanding).
>
I don't have a comprehensive list, but I have been taking the Longman
defining vocabulary (2148 words) as an initial approximation, and trying to
represent those concepts (possibly more than one per word) in the COSMO
ontology, together with other concepts required to describe and reason with
those. Among the most basic concepts are really abstract things like object
and attribute and event, too primitive to logically define, and represented
only by the relations among them - and comprehensible to people mostly by
reference to examples. I would consider "Mass" as primitive - in that case,
a "PhysicalObject" (as defined in COSMO) would not be a primitive because it
can be necessarily defined as an Object that has Mass; nevertheless, it
would be hard to have a perspicuous FO without the notion of PhysicalObject.
I have over 7000 classes (types)in the ontology, but many of those are
probably not primitive, they are only included to make it easier to create a
natural language interface to the FO. So at this point I haven't tried to
tease out the true primitives from decomposable concept representations. (02)
Pat Hayes has mentioned that all of his time theories can be "expressed by"
(Pat Hayes's phrase) axioms containing only three classes, time point, time
interval, and duration, plus some relations among them. Those three are
among the concepts I would consider as primitive, and the different time
theories that can be expressed using those common concepts may be logically
incompatible, but they can be represented as theories and not as part of the
basic ontological commitment of the FO itself. (PatH may not agree with
this terminology). There is no logical contradiction in an ontology
*describing* logically contradictory theories - a contradiction would occur
only if the theories were all asserted to be true. So the primitives are
those things that we use to describe all the things about which we may
disagree. (03)
Numbers would be primitives, and some other mathematical concepts. So would
the concepts related to physical space such as spatial interval (interpreted
in a single motion frame and independent of relativity), and those can be
linked to more abstract notions of space without rendering the physical
space as decomposable, because there are aspects of physical space that are
not susceptible to complete definition. Many things that we can directly
perceive would be primitives, such as "force"; there are things we can say
about force other than F=ma. I think that even "person" may be primitive
(though "animal" may not be). I think that "Light" (the form of
electromagnetic radiation) would also be primitive The actual list would
have to be determined by seeing what set of concept representations
ultimately serves to create the preferred ontology elements for a fairly
large group of users. (04)
I hope that it will not actually be necessary to try to precisely define
the borderline between primitive and non-primitive. My point was that we
should include all of the primitives in the FO, but useful basic concepts,
even if they are *not* primitive, could be very helpful in the FO unless
they proved to be controversial, at which point it would be necessary to
make any distinctions that the users feel are important. The most important
criterion is, if some domain needs a concept representation, and it cannot
be expressed logically (to the satisfaction of the user) as some combination
of existing ontology elements, then it would probably have to be included as
a new primitive. My expectation is that, after some initial period in which
the FO is used by, say, at least 50 independent groups, the need to add new
primitives will dwindle to at most a few per year - it may never go
completely to zero. That level of stability would, I expect, provide the
required basis for accurate interoperability. (05)
[IB] > > If I have an issue with this idea, it is one of pragmatism. As an
> aspiration, a common foundation ontology is something I would really
> support. There seems to me to be a couple of practical problems:
>
> * Reaching consensus - ontology is a topic that attracts people with
> strong opinions. Consensus requires compromise, and I don't see much of
that
> going on in this community. In my experience of developing ISO standards,
it
> usually requires a commercial reward to ensure true consensus is met -
> i.e. they all (well, most) stop bickering if they can see some
profitability
> in not bickering. I don't think ontology is at the maturity level where
> huge sums of money depend on its success or failure, so I fear consensus
is
> going to be nigh impossible.
>
That is the primary problem, but I think the difficulty has been greatly
overestimated. Your point about *motivation* is, I believe, precisely the
key to the solution. As long as we ask for voluntary agreement, and as long
as there are no impressive **publicly usable** applications that demonstrate
the utility of some particular methodology, there will be little reason for
anyone to spend a lot of time adapting their personal preferences or
whatever they are accustomed to, so as to accommodate another person's
personal preferences. The solution is to provide some motivation, and the
fastest method would be to pay them - by which I mean that a project that
engages 100 participants (not necessarily all full-time) and funds their
participation, could require that they agree on *some* FO to link their
local ontologies or DBs, and demonstrate interoperability among them. If
the principle of decomposability into primitives turns out to be feasible,
then this process will end up will every local group *still* able to use
their preferred idiosyncratic representations, but able to interoperate with
other groups because by representing their local elements in terms of the
FO, an automatic translation would be possible. This is the fastest method
of creating a good-sized user group -- de novo by direct funding. Since the
applications developed in this project would be public, this could provide
others the incentive to use the FO that this group developed. This is quite
different from an ontology like CYC developed for local use, as the FO
developers are forced to find a way to accommodate multiple viewpoints.
My estimate of $30 million for a three-year project is not outside the
bounds of AI projects; CALO and LarKC each cost several times that. It
would, however, require that some consortium organize to make such a
proposal. Unless there is some indication from a possible funding source
that such a proposal would be seriously considered (and the money is
available) I don't think that any community would even have the motivation
to prepare such a proposal. So at this time I would be very interested to
find a funding source that willing to consider such a tactic that is not
mostly an extension of existing projects. (06)
[IB: more practical problems ] > * Metaphysical choices - most serious
ontologists
> are aware of the metaphysical choices (i.e. the ground rules) of their
ontology. This
> involves questions of how time is managed (3D, 4D Endurant, 4D
> Perdurant, etc.), whether the ontology is extensional or intensional (both
for
> class membership, and how spatial/temporal extents are handled), and
whether
> the ontology is first order or higher order.
>
It may turn out that there are irreconcilable differences on the set of
true primitives, in which case the minority view holders may conclude that
they *cannot* use the FO; such basic issues could be discussed in a
preliminary meeting, and those who can't use the majority choices wouldn't
participate in the FO project. No problem; the only goal is to get a user
community large enough to provide *some* common FO that can be used by all
the others that are not passionate about such abstruse issues (e.g. 99% of
the database developers who might want to interoperate with other). But in
fact I expect that there will be very few and perhaps zero issues that
cannot be reconciled by decomposition into primitives. For example, on the
3D-4D issue, Pat Hayes said (email to UOM-forum Aug. 8, 2009):
"But, for the record, I reach the conclusion from the observation that
anything that can be said in a 4D ontological framework can be transcribed
into a 3D framework based on the continuant/occurrent distinction, and vice
versa. The differences between them, I have concluded, are really nothing
more than a matter of notational choice."
And for extensional/intensional, I can imagine a simple function
extensionOf(?CLASS, ?CONTEXT) that would create a set from any intensionally
defined class of entities existing in a particular context. This should
allow relating the two to each other - in the event there are actually
practical issues that depend on such a distinction. (07)
[[IB]] I once suggested a set of ontic categories on this
> forum and was soundly thrashed for it, so I'd understand if you want to
> send them off-list. Also, getting a clearer idea of what choices all the
> major ontologies took might give us a better idea what common primitives
are
> possible. Again, if folks want to send that to me off-list, I'll
> collate it all anonymously and post it back. (08)
I don't recall that - could you send a copy to me? I'd be quite
interested. (09)
Pat (010)
Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx (011)
> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Ian Bailey
> Sent: Tuesday, February 02, 2010 4:54 AM
> To: '[ontolog-forum] '
> Subject: [ontolog-forum] Foundation Ontology Primitives
>
> Hi Pat (I won't qualify which Pat, as I'm pretty sure the other one has
> me
> on his filter list),
>
> In the thread that's been running, you indicate that you believe there
> are
> some common ontic primitives that can be shared across multiple
> ontologies -
> e.g. as a foundation. Do you have a clear idea of what these might be ?
> (some examples would really help my understanding).
> (012)
[[PC]]
> The first problem may be overcome by shear will - if enough people take
> a
> positive approach and really want to get it done, it might happen. The
> second issue is much more thorny, and that's why I asked what you
> thought
> the primitives were.
>
> Cheers
> --
> Ian Bailey
> www.modelfutures.com
> ian@xxxxxxxxxxxxxxxx
>
>
>
>
>
>
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