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RE: import qus <-- RE: imports + metadata

From: Paul Vincent <pvincent@tibco.com>
Date: Thu, 3 Apr 2008 07:00:08 -0700
Message-ID: <8F4A4531BB49A74387A7C99C7D0B0E0503D54109@NA-PA-VBE02.na.tibco.com>
To: "Dave Reynolds" <der@hplb.hpl.hp.com>
Cc: <public-rif-wg@w3.org>

Thanks Dave - makes sense. 

Possibly the term "import" would be better replaced by "reference" as in
knowledgebase1 references knowledgebase2 for the use you describe? 

Of course, it might also be useful to be able to dynamically "load" (and
"unload") knowledgebases [which has also been known in the PR world -
ref Nexpert Object]. Whether this is a "control" mechanism that is
irrelevant to RIF, or a rule action for inclusion in RIF, is somewhat
debatable for PRD. Again, I've no idea whether conditional inclusion (or
exclusion) of rulesets is useful in the semantic web world (in the
interchangeable rulesets covered by RIF, that is). 

Paul V 

> From: Dave Reynolds [mailto:der@hplb.hpl.hp.com]
> Paul Vincent wrote:
> > Imports: A few qu's.
> > 1. Is this something that is quite common in the semantic web
> > knowledgebase world? AFAIK its not the case in the commercial prod
rule
> > world, other than maybe as a rule mgmt issue (ie not as a deployment
/
> > interchange issue).
> 
> Yes. It is very common to have one ontology build upon (import)
multiple
> other ontologies produced by different groups. It seems to be a
> fundamental use case in RIF is to take one rule from one group and
> re-use it.  We certainly had "merge rule sets" as a phase 1
requirement
> and the import mechanism seems to me to be part of our answer to this.
> 
> > 2. By "including" some knowledgebase, presumably you are doing so
> > because it is external (if it wasn't you could collapse it in-situ
> > before interchange). How can you "guarantee" you know such an
external
> > KB's content?
> 
> You are importing a URL, whatever that URL gives you is what you
import.
> In the case of an http URL then it is whatever results from an http
GET
> operation.
> 
> > By contract? By version no or metadata?
> 
> ? Sorry, don't follow the question.

[PV>] If all you have is a URL to reference a knowledgebase, then the
URL presumably represents an entity that could be a specific version.
You wouldn't get the equivalent of a web services dialog to identify the
"service" (knowledgbase) required. 

> 
> Dave
> --
> Hewlett-Packard Limited
> Registered Office: Cain Road, Bracknell, Berks RG12 1HN
> Registered No: 690597 England
> 
> 
> > For PRD this is not necessary for rule interchange at this time (but
it
> > could be something that is really required by the semantic web
folks, in
> > which case I abstain).
> >
> > Paul Vincent
> > TIBCO | Business Optimization | Business Rules & CEP
> >
> >
> >> -----Original Message-----
> >> From: public-rif-wg-request@w3.org
> > [mailto:public-rif-wg-request@w3.org]
> >> On Behalf Of Dave Reynolds
> >> Sent: 01 April 2008 22:48
> >> To: Sandro Hawke
> >> Cc: public-rif-wg@w3.org
> >> Subject: Re: imports + metadata
> >>
> >>
> >> Sandro Hawke wrote:
> >>> I'm brainstorming here (sitting in OWLED)....
> >>>
> >>> I wonder about having both:
> >>>
> >>>       import   and   importMeta
> >>>
> >>> 'import' of a RIF document would merge in the rules in that
document
> >> With renaming of locals presumably.
> >>
> >>> 'importMeta' of a RIF document would merge in the metadata and
also
> > the
> >>>       triples which encode the syntactic structure (which we
haven't
> >>>       standardized but we should, and Axel made a proposal [1]
> >> Sounds fine for metalevel hacking but feels like a phase 2 issue.
> >>
> >>> 'import' of an OWL XML file [2] or an RDF/XML-file which is an
> >>>       owl:Ontology would (conceptually merge in the OWL-DL axioms,
> >>>       ignoring all triples not playing a role in the ontology
> >> How do you know an RDF/XML file contains an OWL Ontology,
specifically
> >> one to be interpreted as DL? You can't. That why we original
proposed
> >> the DataSet ontology to allow us to describe data models and
> > entailment
> >> regimes so you can say "this is an RDFS source which I would like
to
> >> interpret with full D-entailment semantics" or whatever.
> >>
> >> The original data model identification proposal [*] still seems to
me
> >> like a feasible approach (I know I'm biased :-)). Of course it
would
> >> have to be updated to cope with how far RIF has diverged from the
> >> RDF-compatible form envisaged at the time that was written. You
would
> >> basically have the object of the "import" directive be a set of
> > metadata
> >> describing the source and entailment regime. If Harold/Michael's
new
> >> metadata proposal wins the day then that would be expressed as a
set
> > of
> >> Frames though I don't know how to do bNodes in frames.
> >>
> >>> 'importMeta' of such a document would give you the triples (ie the
> >>>       triples which encode the syntactic structure of the
ontology).
> >>>       I'm not sure how you say you want OWL-Full inference or RDFS
> >>>       inference or something
> >> Surely the entailment regime is more relevant for import than for
> >> importMeta?
> >>
> >>  > -- I think you "import" rules which
> >>>       implement that inference, but the import is understood to be
> >>>       symbolic -- you're allowed to use your own equivalent
> > reasoner.
> >> Given that not all the inference can be implemented as rules that
> > seems
> >> like a slightly awkward overloading of import but it is a plausible
> >> alternative to the metadata approach.
> >>
> >> Dave
> >>
> >> [*] http://www.w3.org/2005/rules/wg/wiki/Arch/Data_Sets
> >> --
> >> Hewlett-Packard Limited
> >> Registered Office: Cain Road, Bracknell, Berks RG12 1HN
> >> Registered No: 690597 England
> >
> >
> 
> 
Received on Thursday, 3 April 2008 14:01:02 GMT

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