I think that you have a point. (01)
A previous e-mail used the word "harmonizing" rather than "linking" and
I think that it captures the essence of the process a bit better from an
application developer's standpoint. (02)
I would like to see competing sets of "harmonizable" ontologies
described in repository where I can read reviews and discussions about
the kinds of issues that I need to consider in choosing a starting set
and planning for the harmonization of the chosen set with my client- or
industry-specific terms and relationships. (03)
Ali Hashemi wrote:
> Hello all,
> I've read the discussion with interest, and it's very interesting how
> much overlap there has been with my thesis. Unfortunately, I cannot
> share this until next week, but it will be made available online.
> Onto some specifics:
> My thoughts on the subject indicate that foundation ontologies are
> inadequate. They each capture the biases of what people consider to be
> foundational concept. It is difficult to identify what is being said.
> However, I sympathize with Pat C's vision. Though I think an ontology
> repository is more suitable than simply an FO.
> Using a central repository, you might then pick a subset of theories
> (modules) for which to construct your ontology.
> We're not /combining/ ontologies, we're linking them in useful ways.
> So to take Pat H's illustration of the 3D vs 4D accounts, while they
> are in metaphysical opposition, they share patterns of thought, of
> logic. There _/are/_ (useful) similarities, just as there are differences.
> Moreover, they share a language, and describe the same phenomena.
> There are links between the two accounts.
> They might not be exactly primitive in the sense that they are the
> "atoms" from which everything else is built. But they do reuse basic
> logical concepts. I
> The repository architecture I propose in my thesis uses this notion.
> It is similar to the idea of metaphor -- how is the solar system
> similar to an atom? We are mapping substructures from one concept to
> another. Is there something special about these patterns?
> [Begin Pat C1]
> > Both of these common cases are consistent with, and can benefit from,
> > using a logically consistent set of ontological representations of the
> > primitive concepts that can accurately describe the alternatives.
> [End Pat C1]
> [begin Pat Hayes1]
> Plain flat wrong. Provably wrong, in fact, in this case. There is no
> such set of primitive concepts for these ontologies. (Think about it
> for a second: the only concepts in most of them were those of
> timepoint and time-interval, and in all but the simplest, these are in
> fact interdefinable, so one can make do with one. What more
> "primitive" concepts can one reduce this set to?)
> [end Pat Hayes1]
> I disagree (Pat H). Both these accounts use orderings. They share
> many logical structures. There is indeed an undercurrent that pervades
> both accounts of time, especially if we consider accounts of time as
> expressed in say, FOL.
> [begin Neil]
> Pat, you said "Again, you seem here to be talking about a comparative
> meta-theory of alternative ontologies, a kind of uber-meta-ontology
> which talks about ontologies rather than about the world that those
> ontologies describe. This is an interesting-sounding idea, but I have
> no idea how to begin approaching it."
> This sounds like the issue The Open Group solved with its Model Driven
> Architecture with XMI, a meta-meta-data specification for importing
> and exporting data models from different tools that however all
> encoded with XML. What you are discussing is I believe the path to
> the ontology interoperability solution. What is needed is exactly
> what you stated, a framework that will allow both machine and
> ontologist to tell at what levels two ontologies are ambiguous and at
> what nodes they become disambiguous.
> This sounds to me to be analagous to determining at what level two
> people are in complete agreement on an idea and at what point they
> agree to disagree, marking those points distinctly so that others can
> discern to which they want to subscribe.
> I would say that perhaps even a rating system could be devised based
> on this idea that could tell the level of congruence between two
> ontologies and give the user an idea of the continuity based on this
> rating-- which could even be something as simple to use as a
> percentage at each node of the ontology.
> [end Neil]
> The functionality Neil describes here is almost exactly what the
> semantic mapping algorithm chapter of my thesis elaborates.
> I would like to iterate here that what we may often de-emphasize, is
> that we're capturing _/parts of reality/_ through languages.
> when pat states:
> [begin Pat Hayes2]
> But my point is that there is only one entity, in fact. And it is
> important for an ontology to be able to say this, and clearly draw
> appropriate conclusions. If I am in a room and nobody else is in it,
> there is one person in the room. Not two people, one of them 4-d and
> one of them 3-d.
> [end Pat Hayes2]
> There is surely only one of Pat, but language affords (at least) two
> ways of describing him; of creating a coherent account of him.
> We would do well to heed some insights from Marshall McLuhan. "The
> medium is the message." An ontology is the interplay of a number of
> media, not least of which is language - generally some formal logic.
> Ontologies rendered thusly reflect the expressivity and theories of
> the language.
> Possibly a mundane point, but they should also highlight the ways in
> which inconsistent theories may share similar structures. Indeed, if
> one were to construct a _model_ (in the logical sense), of pat using
> 3-d and 4-d views, there would be much in common between the two.
> The interesting question is how they relate. Not that a merge would
> simply render the resultant account incoherent. But in what ways are
> they similar and how to they differ?
> [begin John S]
> There are many good resources available on the WWW, but I am not aware
> of anything that comes close to meeting the above criteria for
> maintaining, evaluating, relating, and organizing an open-ended
> and growing collection of ontologies. If anyone knows of any such
> things, please let us know.
> [end John S]
> one should be forthcoming.
> [being Ed b]
> If I were more conversant with the Cyc ontology, I probably would
> have known which collector I wanted in each case, but that is after my
> domain analysis tells me what axioms I need. Now, once
> I had determined what I meant, I found a Cyc concept had all the
> needed axioms, including ones I would have forgotten. OTOH, I had to
> reject two similar concepts because they included axioms I didn't
> mean. Without Cyc, I defined (most of) the same general concepts, but
> it took me several tries to get all the axioms right.
> [end Ed b]
> how serendipitous, my ontology design algorithm (chapter) partially
> addresses, and at the very least alleviates a lot of the problems
> here. it allows ontology designers to define a relation semantically,
> with little need to navigate the syntax and grammar of a particular
> formal logic.
> [begin P hayes3 ]They are all "atomic". (Well, virtually all: all the
> 'natural kind' concepts, as opposed to artificial combinations such
> as "French women between the ages of 25 and 50".) Just look at a
> first-order theory: all the names in it are on an equal footing; none
> are more 'primitive' than another, and they have no internal
> conceptual structure which would permit their being decomposed into
> something simpler or more elemental.
> But surely the time catalog is a clear case of this non-uniqueness. I
> fail to understand how you cannot see this, it seems so obvious. What
> would you reduce all of it to?
> [end P hayes3]
> I would reduce it to theories it is reusing. In the case of time,
> orderings. In the case of space, orderings, groups, symmetries etc.
> There are more links than simply conservative and non-conservative
> extensions. More than simply generalization and specialization.
> Briefly, the repository architecture i've outlined in my thesis
> consists of two main components:
> "Abstraction Layers" -- abstraction layers are connected with one
> another via representation theorems.
> "Core Hierarchies" -- no core hierarchy may share a non-conservative
> extension with another in the same abstraction layer.
> It shares some similarities withe the lattice of theories that John
> Sowa has spoken of, but it has other properties which enable the above
> two mentioned algorithms.
> The repository isn't necessarily an account of the world. It's an
> account of what's expressible in a formal logic (in the case of my
> implementation, Common Logic). It is silent as to the disagreements of
> the Upper Ontologists. It is more interested in finding useful
> patterns as expressible in language, and only then, how these patterns
> are related to grounded concepts.
> This idea isn't an attack on UO's, but rather a complement. The
> different views, and biases as captured by UO's are valuable. It's
> simply that they are not exclusively "true". The repository described
> in my thesis unifies these within the language of expression.
> It also consequently enables to pretty useful algorithms. One for
> semantic mapping and another for ontology design.
> The semantic mapping algorithm uses a centralized repository to
> conduct ontology alignment between /n/ or more ontologies.
> The ontology design algorithm intelligently navigates the repository
> to match an agent's intended semantics to sets of axioms.
> Sorry for the tease, but next week my thesis will be bound and in the
> libraries, so i'll be able to link the document then.
> (PS if someone has an interesting project, i'd likely be interested
> now that my Master's is complete ;) .)
> Ali Hashemi
> MASc (waiting to officially convocate)
> Semantic Technologies Laboratory
> University of Toronto
> (•`'·.¸(`'·.¸(•)¸.·'´)¸.·'´•) .,.,
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