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Re: AW: [ontolog-forum] Current Semantic Web Layer Cake

From: Kuldar Taveter <kuldar@csse.unimelb.edu.au>
Date: Sat, 04 Aug 2007 11:59:35 +1000
Message-ID: <46B3DD87.3050000@csse.unimelb.edu.au>
To: Valentin Zacharias <Zacharias@fzi.de>
CC: Pat Hayes <phayes@ihmc.us>, "John F. Sowa" <sowa@bestweb.net>, "[ontolog-forum]" <ontolog-forum@ontolog.cim3.net>, Ivan Herman <ivan@w3.org>, Juan Sequeda <juanfederico@gmail.com>, SW-forum list <semantic-web@w3.org>

I must say that I totally agree with Valentin. It is not possible to 
solve the interoperability problem by imposing
a set of standards "from above". The world is too diverse a place to 
assume that everyone is going to use them.
Just a  simple example: when agents need to reconcile two differently 
represented ontologies, neither of which cares
about SWeb interoperability "standards", then perhaps the only way to 
reconcile them is to use instances of the
concepts described by them.

Best regards,

Kuldar Taveter, PhD
Research Fellow
Department of Computer Science and Software Engineering
The University of Melbourne, Australia
Phone: +61 3 8344 1403
Fax: +61 3 9348 1184
Homepage: http://www.cs.mu.oz.au/~kuldar/

Valentin Zacharias wrote:
> Hi!
> Pat Hayes said:
> [...]
>> I am slightly concerned that this peculiar kink in the layer 
>> cake has been put there deliberately to make it possible to do an 
>> end-run around a unifying logic. Which when one takes into account 
>> the whole point of "Unifying", would IMO be a pity.
> [...]
> I can understand that people insist on Semantic Web languages to have a
> formal, or even a model theoretic semantic. What I don't get is that you
> (and John F. Sowa in other emails) seem to insist that this must be classic,
> FOL like, monotonic semantic and that all formalisms with different
> semantics (or kinds of reasonings) have no place in the Semantic Web. 
> To me it seems obvious that these semantics cannot be the exclusive basis
> for reasoning on a global,open knowledge based system, because:
> 1) These semantics do not consider quantitative aspects (e.g. 5000 locations
> state that a(mike), only 2 state that b(mike)), don't allow for closed world
> reasoning, do not consider trust, require very strict global consistency....
> Because of this they cannot reflect the intuitions and expectations of
> humans about what should be concluded from a set of statements as unordered
> and ungoverned as the web.  Hence actual applications will in any case use
> other notions of truth and entailment (or come to conclusions that are not
> accepted by the users and probably not very useful).* 
> 2) Should we really ever get reasoning semantic web agents, isn't it
> preposterous to assume that will rely exclusively on logical deduction?- Why
> not induction, abduction, analog reasoning, data mining, nlp, ir, simulation
> ... Doesn't this mean that in any case there will never be a complete
> mapping between the "proof" and the "logic" layer (as currently envisioned)?
> I also don't see how any kind of inference can be done on web scale without
> a large (essentially heuristic) information retrieval component trying to
> get the relevant statements (considering what we know about the complexity
> of inference algorithms) - again breaking the direct logic layer-proof layer
> mapping. 
> my opinion in short: we don't have any semantics that covers everything that
> is needed (and I don't even see one at the horizon), hence we should not
> stifle innovation by insisting on one thats clearly inadequate for the task
> at hand. 
> cu
> valentin
> *: given the large amount of research into things like circumscription,
> uncertainty reasoning, rdf/dl+contexts etc. I was under the impression that
> this is a SW-community mainstream position. 
Received on Saturday, 4 August 2007 02:00:24 UTC

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