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Re: [ontolog-forum] Foundation ontology, CYC, and Mapping

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "doug foxvog" <doug@xxxxxxxxxx>
Date: Tue, 16 Mar 2010 12:15:25 -0000 (GMT)
Message-id: <23288.>
Chris Menzel wrote:
> On Mar 15, 2010, at 12:05 PM, Cory Casanave wrote:    (01)

>> One comment, re: Adding a contradiction to any consistent theory causes
>> it to degenerate to the absurd theory.    (02)

>> One pragmatic reality of architectural work is that theories do not
>> agree. Particularly in the realm of business related modeling there are
>> clearly different interpretations and opinions about the same thing.  So
>> we have seemingly conflicting theories but we agree that the theories
>> describe the same entities that exist or may exist. Such conflicting
>> theories are normal and even desirable in our discourse.    (03)

> Absolutely.    (04)

>> One capability that a knowledge technology should be able to provide is
>> the identification of these conflicts and the source of assertions and
>> conflicts.    (05)

> Yes, that is one thing that one hopes to get out of (among other things)
> the use of automated reasoning tools.    (06)

>> One thing that this requires is the ability to assert that 2 symbols
>> represent the same entities or concepts, yet may make very different
>> (and perhaps conflicting) assertions about these entities. In the OWL
>> world, sameAs is frequently used for this, but sameAs seems to strong a
>> commitment.    (07)

> There is nothing that I can see in the semantics of "owl:sameAs" that
> would enable it to be used to indicate that two different symbols "may
> make very different (and perhaps conflicting) assertions" about about
> their denotations.    (08)

What is missing here is the idea of contexts.  Statements made using terms
equated by "owl:sameAs" are usually made by different asserters in different
contexts.  If the different contexts make conflicting assertions, it is
the contexts which conflict.  Such conflicts can also occur with different
users of the same term, or even a single individual who makes statements
using the same terms in different contexts.  E.g., in one knowledge base
might state that dbp:BarakObama is an Illinois senator, while another might
state that he is president of the USA.    (09)

> From the OWL reference document:  "owl:sameAs is used
> to state that two URI references refer to the same individual."  If, in
> fact, two URI references are used to say things that cannot be true of one
> and the same thing, then declaring one to be "owl:sameAs" the other will
> simply lead to logical inconsistency, i.e., absurdity, full stop.  The
> only way to avoid it is to withdraw the assertion or alter what is said
> about the individual in question by means of those URI references.    (010)

>> EquivelentClass is closer,...    (011)

> I don't see how.  "<A owl:equivalentClass B>" means nothing more or less
> than that the classes A and B (or, if you like, the classes referred to by
> the names "A" and "B") have the same members.    (012)

Actually, that they have the same members in the same context.  In
different contexts, they may have different members.    (013)

> Again, there is nothing
> there that could be exploited to indicate that "very different (and
> perhaps conflicting) assertions" are being made using those names.    (014)

Again, this is only true when restricted to the same context.    (015)

>> In summary, when using ontologies to represent architectures we should
>> embrace conflict ...    (016)

> I think there is an important ambiguity here.  One should certainly
> "embrace conflict" in the sense that one should acknowledge the fact that
> there different outlooks and opinions and that dialog between communities
> with different outlooks and opinions can lead to rich and fruitful
> results.  One should certainly *not* embrace conflict in the sense of
> allowing logical inconsistency within an ontology.    (017)

Note that reasoning need not use but a single ontology.  Reasoning can
use a vocabulary ontology to define the classes and relations which it
uses, a theory ontology to define rules about those classes and relations,
one data ontology to specify instances of those classes being considered,
and a second data ontology specifying the context, including instances of
the relations applied to the class instances and spatio-temporal re-
strictions on the statements.    (018)

>> and not consider conflicting theories as absurd.    (019)

> Are you suggesting someone has?  No one has suggested that, if T1 and T2
> are *jointly* absurd (i.e., if their union is logically inconsistent),
> then T1 and T2 are *individually* absurd.  The only that would be absurd
> would be to merge incompatible theories without resolving the conflict
> (which, as you note, might require dialog between the advocates of the
> theories).    (020)

Agreed.    (021)

>> Conflict is an indication of differing opinions and interpretations,
>> both normal and expected conditions of dialog.    (022)

> Of course.    (023)

It is also an indication of different contexts.    (024)

-- doug f    (025)

>> This differs from the logical or mathematical pragmatics where any
>> inconsistency is an error.    (026)

> I'm not certain what you mean by "logical or mathematical pragmatics" but
> in any context "error" is a psychological notion that is of at most
> sociological, historical, or legal significance.  The only important point
> for purposes here, it seems to me, is that, in any context, logical
> inconsistency ("absurdity" in John's technical sense) is something that
> must be avoided in one's final product and removed (as far as possible) if
> detected.  This is all quite compatible with your entirely correct remarks
> about the reality of diverse outlooks and opinions, the importance of
> dialog in resolving conflict, etc etc.
> Chris Menzel    (027)

doug foxvog    doug@xxxxxxxxxx   http://ProgressiveAustin.org    (028)

"I speak as an American to the leaders of my own nation. The great
initiative in this war is ours. The initiative to stop it must be ours."
    - Dr. Martin Luther King Jr.
=============================================================    (029)

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