RE: [RIF] Reaction to the proposal by Boley, Kifer et al

+1

Indeed, I suspect the nature of rules (such as inference / production
rules) changes once you move to RDF. Effectively, RDF is a low-level
data format - very powerful, but not aimed at readability etc. So where
I can see (the semantic web community) wanting to exchange rules that
reason over RDF, or mapping rules and data models to some RDF
representation as a "description language", the conventional / more
common rules for interchange will be those that Gary describes - written
against some XML schema representing some real-world object model and OO
implementation.

Cheers,
Paul Vincent for Fair Isaac 

> -----Original Message-----
> From: public-rif-wg-request@w3.org
[mailto:public-rif-wg-request@w3.org]
> On Behalf Of Gary Hallmark
> Sent: Wednesday, May 03, 2006 7:30 PM
> To: public-rif-wg@w3.org
> Subject: Re: [RIF] Reaction to the proposal by Boley, Kifer et al
> 
> 
> I'm not sure what exactly is entailed by first-class citizenship of
> RDF/OWL in RIF.  Oracle has a small but growing number of customers
who
> are adopting Semantic Web technologies, e.g. in the life sciences
area.
> We don't object to meeting their needs.  On the other hand, the
majority
> of our customers and developers are using non-semantic web
technologies
> such as web services, BPEL, XQuery, XmlSchema, XSLT, etc. combined
with
> Java and SQL, to build their applications.  We cannot require them to
> adopt RDF or OWL in order to use RIF.  Therefore, XML data must be
> supported by RIF, and RIF must be fully functional for the case where
> only XML data is used.
> 
> Alex Kozlenkov wrote:
> 
> >Guys
> >
> >There are a few general concerns we have about the points raised by
> >Peter in that RDF/OWL should be first-class citizens in RIF. Firstly,
> >the production/reaction rules should play a good part of the
standard.
> >As I understand it, it has been an industrial requirement all along,
> >certainly from our company. PR/RR have their own semantics that is
not
> >directly compatible with, say, RDF deduction.
> >
> >Secondly, tying RIF closely to OWL would effectively assume that
> >well-designed OWL ontologies become a prerequisite to do any
meaningful
> >form of inference. The reality of large software projects is that it
may
> >be prohibitively expensive to construct and maintain a consistent and
> >complete set of reference ontologies even for a subset of the main
line
> >of business. In research, it may work well, while in the real world,
> >only very stable parts of the business could be covered while other
more
> >volatile parts may stay outside of the OWL glasswork. What I am
saying
> >is that rules may have to play a pragmatic role than other parts of
the
> >Semantic Web technologies hence tying them closely with these parts
may
> >hinder the success of the rules technologies per se. Bad ontologies
can
> >unfortunately also be easily constructed and what about reasoning in
> >their presence, I'm worried about how the system will behave in this
> >case.
> >
> >I was wondering if you think these two observations are making sense.
> >
> >Alex Kozlenkov
> >
> >Advanced Technologies Group
> >Betfair Ltd.
> >
> >-----Original Message-----
> >From: public-rif-wg-request@w3.org
[mailto:public-rif-wg-request@w3.org]
> >On Behalf Of Peter F. Patel-Schneider
> >Sent: 03 May 2006 12:27
> >To: kifer@cs.sunysb.edu
> >Cc: public-rif-wg@w3.org
> >Subject: Re: [RIF] Reaction to the proposal by Boley, Kifer et al
> >
> >
> >From: Michael Kifer <kifer@cs.sunysb.edu>
> >Subject: Re: [RIF] Reaction to the proposal by Boley, Kifer et al
> >Date: Wed, 03 May 2006 01:35:08 -0400
> >
> >
> >
> >>"Peter F. Patel-Schneider" <pfps@inf.unibz.it> wrote:
> >>
> >>
> >>>I, on the other hand, have some serious concerns with the proposal.
> >>>
> >>>
> >
> >
> >
> >>>I worry about using a substitution in the basis of the semantics of
> >>>conditions, in particular because the rest of the semantics of
> >>>
> >>>
> >conditionals
> >
> >
> >>>(including the semantics of existentials) are unspecified in the
> >>>
> >>>
> >proposal.
> >
> >
> >>>Will this actually end up close to a known logic?
> >>>
> >>>
> >>This is based on a known logic: infinite Herbrand interpretations.
> >>
> >>
> >
> >Reference, please.
> >
> >
> >
> >>It is easy to extend this semantics for general, non-Herbrand
domains.
> >>But this will be useful only for the FOL dialect. The others will
have
> >>
> >>
> >to
> >
> >
> >>fall back on Herbrand interpretations.
> >>
> >>
> >
> >I worry about situations like the following.
> >
> >Suppose that there (only) are two constants, T and F, and (only) one
> >one-place function, N.  Does it then follow from the following two
facts
> >
> >	N(T) = F
> >	N(F) = T
> >
> >that
> >
> >	Ax Ey x = N(y)
> >
> >
> >[...]
> >
> >
> >
> >>>I worry about the connection between the proposal and RDF and OWL.
> >>>
> >>>
> >I do
> >
> >
> >>>not view it as appropriate to relegate existing Semantic Web
> >>>
> >>>
> >languages to
> >
> >
> >>>an add-on query interface.
> >>>
> >>>
> >>Why?
> >>
> >>
> >
> >Because we are supposed to be working within the confines of the
> >Semantic Web.
> >
> >
> >
> >>A query interface is a very general thing.
> >>
> >>
> >
> >Is it really?  It instead seems to me to be much more like a ghetto.
In
> >particular, the proposal uses a ternary predicate for RDF triples,
> >divorcing RDF facts like ex:a rdf:type ex:b from a representation
> >as ex:b(ex:a).
> >
> >
> >
> >>It can range from seamless
> >>integration (e.g., in FOL-based dialects)
> >>
> >>
> >
> >How?  Can a query interface actually achieve complete integration?
For
> >example, can a query interface reasonably support a rule language
that
> >is
> >oblivious to the source of information, i.e., what sort of rule could
be
> >used to produce the transitive closure of the binary relation R,
where
> >some
> >facts about R are in RDF and others are in the form of conditionless
> >rules?
> >
> >
> >
> >>to Rosati and Eiter et al. style integration,
> >>
> >>
> >
> >Perhaps.  These sorts of integrations do make a firm divide between
> >"rule"
> >predicates and other predicates, so it may be more natural to "query"
> >the
> >other predicates.  I am not totally convinced, even in this case.  I
> >note
> >that the papers by Rosati et al. do not have a special query
interface
> >for
> >the other predicates.
> >
> >
> >
> >>to external calls to ontologies.
> >>
> >>
> >
> >Well, I suppose that if the ontology cannot be changed then there is
no
> >problem with a query interface.
> >
> >
> >
> >>Different degrees of
> >>integration will be appropriate for different dialects. (For
instance,
> >>
> >>
> >what
> >
> >
> >>would be the appropriate integration for PR rules?)
> >>
> >>
> >
> >Good question.  What answers are reasonable in this proposal?
> >
> >
> >
> >>	--michael
> >>
> >>
> >
> >Peter F. Patel-Schneider
> >
> >
> >
> >
>
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Received on Wednesday, 3 May 2006 21:57:58 UTC