[topicmapmail] Making ontologies : RDF vs TM
Lars Marius Garshol
larsga@ontopia.net
Tue, 02 Nov 2004 10:54:08 +0100
* Murray Altheim
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| [Ann's thoughts on identity and equivalence]
|
| I can't speak to the context of Ann's statement, but from what
| you've provided it *seems* to be making some kind of up-front
| assumption of the purity (author's intention?) of the Topic Map
| prior to any sort of local merging. It doesn't *seem* to solve this
| problem at all. How do you see it as, in part, being a solution? I
| don't myself see it.
The point is that all the solutions to the identity problem that have
been put forward so far are in a sense "absolute". Either your subject
identifiers are equal, or they are not, and if they are, you need to
merge. And there is no standard way to unmerge. Similarly, if you
declare the SSN occurrence to be unique, that may be useful, but it
doesn't affect this. You still have only one view of what the
identities are.
If you allow different "theories of identity" to be constructed, each
one of which is effectively an equivalence relation, and applied at
will without losing the original data, you have a solution to the
problem of only a single "theory of identity" being applicable at any
given time. Which gets you away from the absoluteness of identity.
Of course, this is not an absolute problem, in the sense that any
model that you start building (from an XTM document or something else)
is going to contain lots of little
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| > | (I use Topic Map termino- logy here because I am also emphasizing
| > | that I think we can still use Topic Map technology to do information
| > | or "knowledge" modeling; we just need to alter our approach a bit
| > | when talking about subject identity.)
| > How do you think we need to alter our approach? (I'm asking because I
| > couldn't find an explanation of this in your email. Which is not to
| > say it may not have been there. :-)
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| Simply by being very clear about context, i.e., that an individual
| Topic Map is not a statement of universals. By way of example, if
| one looks at the OWL specification (or many, many others), it's
| not stated anywhere that OWL is a very specific set of semantics
| *within a specific community, for a specific purpose*. There is,
| at least to the unenlighted, the idea that OWL's subclass, for
| example, is a subclass suitable for all uses of "subclass", as if
| one didn't even need to delve into how Description Logics, or the
| W3C-specific version of DL-within-OWL defines class, and that whole
| recursive problem of needing to further define the words used in
| the definition of class, etc. etc. etc.
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| In other words, OWL acts as if it has some sort of universal
| semantic validity. And 90% of those using OWL won't run into any
| problems because they would be, like you said earlier in this
| message, their IT systems just seem to "work." Problem is, of
| course, that OWL was designed as a universal, so when your IT
| system talks to someone else's there's no way of really capturing
| the contextualized differences between the built-in, contextualized
| implementations, such that errors or problems that will occur (even
| if they're not noticed until someone's bank balance is wrong, a
| military ordnance is sent to the wrong place, or you receive a
| sex toy in the mail instead of a baking tin). Hmm. Might not be a
| problem for some people, but point is, the kinds of errors that
| crop up might not even be noticed, which is more a problem than
| if they are. People tend to filter out incongruities in understanding
| between each other when communicating.
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| > | The problem is that almost the entirety of western culture is built
| > | upon thousands of years of thinking about things as subjects, as
| > | categories, as identifiable "types", when I believe reality is
| > | telling us otherwise.
| > I agree.
| > | My feeling is that it isn't crackable, that we'll never have any
| > | kind of universal ontology because there are almost no shared
| > | universals amongst all people. I agree again.
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| Perhaps the only thing we *really* need do is emphasize context and
| make sure we include it and use it appropriately. PSI sets are
| published not as universal ontologies but as agreed-upon statements
| about a domain by an individual or group, within a particular
| domain of time, community and purpose. It may be that our notion of
| scope is weak in implementation, but OTOH, there's no inherent
| limitation in our ability to construct complex relationships
| creating context, such that some "collection of relevant conditions
| and surrounding influences that make a situation unique and
| comprehensible" could be reified as a Topic and used to scope a
| specific Topic Map construct. It's not "a cat is on a mat," it's
| "a specific cat is on a specific mat at a specific time", with the
| devil in the details defining "specific", and we're still leaving
| out C.S. Peirce's Thirdness, which is where we begin to derive
| meaning, in contextualized human interpretation, not in the statement
| itself.
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| So another way of putting this is to take every instance of a logician
| using the "universal quantifier" (i.e., "for all") and add a wrapper
| of context around their head, like a big Turkish towel. There is no
| and can be no universal quantifier, despite what every FOL advocate
| might believe.
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| Murray
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| ---------------
| [1] "Context Dynamic and Explanation in Contextual Graphs", Br=E9zillon, =
P.
| http://www-sysdef.lip6.fr/~brezil/Pages2/Publications/26800094PB.pdf
| [2] "Operational Knowledge Representation for Practical Decision Making",
| Jean-Charles POMEROL, Patrick BREZILLON
| http://www.hicss.hawaii.edu/HICSS_34/PDFs/DTISA02.pdf
| [x] "Explanation as Contextual Categorization", Leslie Ganet, Patrick
| Br=E9zillon, and Charles Tijus.
| http://www-sysdef.lip6.fr/~brezil/Pages2/Publications/26800142LG.pdf
| [x] "Modeling and Using Context: Past, present, and Future", Br=E9zillon,=
P.
| http://ftp.lip6.fr/lip6/reports/2002/lip6.2002.010.pdf
| ......................................................................
| Murray Altheim http://kmi.open.ac.uk/people/murray/
| Knowledge Media Institute
| The Open University, Milton Keynes, Bucks, MK7 6AA, UK .
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| A schoolteacher at a Bush event was on her way to the bathroom when
| she was stopped by a volunteer and told she wasn't welcome. The
| volunteer pointed to her T-shirt and said it was 'obscene'. She and
| her two friends (also wearing the same shirts) were escorted out by
| police officers and threatened with arrest if they did not comply.
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| The T-Shirts read: 'Protect Our Civil Liberties'"
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| Shutting Them Up
| http://dneiwert.blogspot.com/2004_10_17_dneiwert_archive.html#10983047=
2470609571
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| Dismantling Democracy
| http://dneiwert.blogspot.com/2004_10_17_dneiwert_archive.html#10983062=
2308006215
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Lars Marius Garshol, Ontopian <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50 <URL: http://www.garshol.priv.no >