Cory suggests that we introduce a new layer to our ontology work: the
layer of context. (This is analogous to the Semantic Web idea that we
separate out ontologies into walled-off zones called namespaces,
though seemingly more difficult, since namespaces are just a matter
of syntax; Cory's contexts seem to be something more complicated.) (01)
Three problems then arise: (02)
1. in addition to building the ontology (or ontologies), which is
hard, we would need to build also a theory (or theories) of contexts
on a level on top of that, which is even harder (03)
2. even if we have a good theory of contexts, and even if we can fit
all our ontologies neatly into contexts (perhaps into different
contexts at different times), we would still need to find a way of
unifying the ontologies themselves, at the ground level, in ways
which will make them interoperable -- but this means finding out what
stands up, ontologically, independently of context (04)
3. would we then need also a second-level theory of the context(s) in
which the theory of contexts itself is formulated/expressed? and a
third-level theory for the contexts in which this second level theory
is formulated? (05)
Certainly, the ontology of ordinary speech acts is itself a good
candidate (low-hanging fruit) for what might be included in a
ground-level ontology; but not, please, an ontology of those speech
acts which are used by a certain very small and very specialized
community when it talks about ontologies.
BS (06)
At 07:12 AM 11/28/2005, you wrote:
>John,
>Ok, now imagine a small hour glass spinning over my head, absorbing all the
>references on this thread takes a while!
>
>In the mean time, there are two points where we were not communicating. The
>"modular" I was thinking of was in terms of a family of related Ontologies,
>or perhaps micro-theories (I will switch to that phrase). In the framework
>I was imagining, the context represented by the micro theory parameterizes
>the axioms. I think I understand your use of "module" to be individual
>"engines", each with a small ontology, interacting with others - essentially
>an agent like system.
>
>Point 2; there is an ontology of speech acts (which is quite interesting)
>but there are also the speech acts about the Ontologies (or micro theories)
>themselves - which may provide some of the parameters for computation based
>on context. To use your example, controlling a bus, airplane, mars rover
>provide a situational context for the axioms specific to that vehicle. The
>speech act about the set of Ontologies also provides context and thereby
>selects what axioms are applicable.
>
>If our UF provided for parameterizing micro-theories by context it would
>then be able to admit seemingly incompatible macro-theories.
>
>I understand the complexities that such parameterization causes for engines,
>but perhaps we can find a tractable subset of unconstrained model
>non-monotonic logics that would suffice. Something like applying the
>parameterization prior to the inference?
>
>-Cory
>
>Ps; An odd example of the speech act mess; Lets say we are charged with
>specifying a "current state" "future state" architecture, each of course has
>the appropriate speech act. <architecture 1> is stated to represent the
>current enterprise. <architecture 2> is stated to be a specification of how
>the enterprise will operate at point in time "C". Now add to this a
>future-state architecture done five years ago - this does not, of course,
>correspond to how the future actually worked out. <Architecture C> is
>stated to be an unrealized plan for timeframe B done in timeframe A. Speech
>act E - what is the difference between these architectures?
>
>-----Original Message-----
>From: ontac-forum-bounces@xxxxxxxxxxxxxx
>[mailto:ontac-forum-bounces@xxxxxxxxxxxxxx] On Behalf Of John F. Sowa
>Sent: Sunday, November 27, 2005 11:45 PM
>To: ONTAC-WG General Discussion
>Subject: Re: [ontac-forum] Neutrality Principle
>
>Cory,
>
>Before getting into the details of your note, I'd
>like to emphasize the point that the the idea of
>concentrating on vocabularies for UF and minimizing
>the detailed axioms is only part of the story. I
>definitely do *not* advocate throwing away axioms.
>But I believe that putting them into a single monolithic
>lump is too inflexible. Even Cyc has subdivided the
>axioms in multiple microtheories, but there's more
>structure needed for interactions among modules.
>
> > Similar to your suggestion of modularity, perhaps
> > the common framework is itself modular in such a way
> > that conflict is explicitly allowed for between its
> > modules. There is a tendency to think of these systems
> > monolithic statements of Truth, and while some have had
> > that intent, it may not be necessary for our purposes.
>
>Yes, I very strongly agree.
>
> > If we instead think of each of these ontological modules
> > as "speech act"(s), an assertion by an individual, group
> > or authority at a particular time. We can have a framework
> > for dealing with a system of these modules that may or may
> > not be in conflict.
>
>Yes. Inferencing and information flow are related, but
>they have different requirements. In communication, the
>most prominent features are the speech acts and vocabulary.
>I published an article that emphasized speech acts and
>their relationship to modularity:
>
> http://www.jfsowa.com/pubs/arch.htm
> Architectures for Intelligent Systems
>
>This article was strongly influenced by John McCarthy's
>Elephant 2000 language, which is based on speech acts.
>The article introduces the Flexible Modular Framework (FMF),
>in which interacting modules pass messages among themselves,
>each one with a tag that indicates the speech act. For
>McCarthy's original paper on Elephant, see
>
> http://www-formal.stanford.edu/jmc/elephant/elephant.html
> Elephant 2000: A Programming Language Based on Speech Acts
>
>A quotation from that article: "Human speech acts involve
>intelligence. Elephant 2000 is on the borderline of AI, but the
>article emphasizes Elephant usages that do not require AI."
>
>My colleague Arun Majumdar implemented a version of the FMF
>while he was living in Palo Alto and had a number of discussions
>with McCarthy about Elephant, speech acts, and related issues
>of logic and reasoning.
>
> > The speech act asserting a set of statements forms one dimension
> > of context for those statements. A set of statements is valid
> > within a context. There are, of course, other forms of context
> > such as authorities/political, physical or situational. All can
> > govern how and when statements within that context are to be treated.
>
>The word "context" has many senses. The speech act indicates the
>purpose of the communication: tell, ask, command, promise, commit,
>authorize, deny, etc. The basic three -- tell, ask, command --
>have been implemented in computer languages for years, but the
>others are important for on-line business transactions.
>
>Another sense of context involves the subject matter, which brings
>in specialized axioms or programs that deal with the information
>content of the message. The kind of axioms required depend on
>both the subject matter and the speech act. One of the basic
>principles of the FMF is that a module should be able to determine
>quickly whether it is capable of handling a message, and if not,
>where to send it.
>
> > Using something like wordnet makes a lot of sense for informal
> > (but still useful) connections, but I don't see how it works
> > for formal ones.
>
>You can think of the modules as having different levels of expertise.
>Some modules may be highly specialized, and others could behave
>like a receptionist, who isn't an expert in anything, but who
>knows enough about the subject to route a message to another module
>that can handle it. The FMF also supports various blackboards, on
>which a module can post messages that are retrieved associatively
>by other modules that are looking for things to do.
>
>Inside a module, there might be a highly specialized and optimized
>program, or there could be an inference engine that does reasoning,
>which could transform a message and generate new messages for other
>modules. So even for the same subject domain, different modules
>could have different axioms (or compiled programs) that do different
>things.
>
>This approach does not rule out monolithic systems, if they are
>needed -- you could take all of Cyc, put a wrapper around it,
>and it would look like a module. But you could also split the
>microtheories or other axioms into different modules that would
>deal with specialized subjects in specialized ways.
>
> > Given such contextual modules you can determine what modules are
> > in conflict with others, and perhaps provide logic to reduce or
> > eliminate the root causes. (For example, the assumption that time
> > is the same for all participants - which works just fine in the
> > context of earth systems but not in the context of space flight).
>
>That's an example where different modules could use the same
>vocabulary about space and time, but different sets of axioms
>for reasoning about them. Even for travel, you need different
>axioms and ways of thinking about driving a bus, guiding a
>Martian rover, sailing a ship, running a railroad, or planning
>a space mission. One set of axioms definitely does not fit
>all applications, even when there is a lot of common vocabulary.
>
> > Almost all human abstractions seem to be highly contextual, yet
> > most logics don't have the mechanisms to deal with it due to
> > the monotonic restrictions.
>
>I certainly agree. OWL, for example, is an extremely limited logic,
>which doesn't even support full FOL. It might be adequate to handle
>the limited kinds of axioms needed for WordNet, but certainly not
>for nonmonotonic, modal, higher-order logics that interface with
>programs that do specialized computation.
>
> > One of the goals for this is to have a wider net for capturing
> > knowledge, much of which is expressed in ways that are imprecise,
> > lacking in detail and contradictory.
>
>Knowledge acquisition, design, problem specification, and many
>related issues involve very different issues that are orthogonal
>to the communication/inferencing dichotomy. That is one more
>reason for breaking up the system into multiple interacting modules,
>each with different kinds and levels of expertise.
>
> > So, in summary, can we find a way to "admit all" instead of
> > least-common denominator by applying context to statements as
> > speech acts from various communities or authorities?
>
>I believe that it's possible, and I also believe that a monolith
>is not sufficiently flexible to handle the job. Modules, along
>the lines we are discussing are a prerequisite, but there's still
>a lot of R & D to do in order to determine the best way to divide
>up various tasks among interacting modules.
>
>John
>
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