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Re: Contextualization ---> Optional bundle in Specialization

From: Satya Sahoo <satya.sahoo@case.edu>
Date: Wed, 27 Jun 2012 18:01:13 -0400
Message-ID: <CAOMwk6yAJr=jsAmZyeonWzxxABimm_wWqsMgd9iRJ2cAChDYCA@mail.gmail.com>
To: Jim McCusker <mccusj@rpi.edu>
Cc: Paul Groth <p.t.groth@vu.nl>, Graham Klyne <graham.klyne@zoo.ox.ac.uk>, Luc Moreau <L.Moreau@ecs.soton.ac.uk>, Provenance Working Group WG <public-prov-wg@w3.org>
>
> What Graham is objecting to (I think) is the idea that ex:Bob in one graph
> is referring to something different from what ex:Bob is referring to in
> another graph. That's not possible in RDF, as while we can have more than
> one symbol (IRI) denote the same resource, it's by definition impossible
> for a symbol to denote multiple resources in different contexts.

++1

Best,
Satya



> The symbol is universally scoped if it is an IRI. If it is not universally
> scoped, it needs to be anonymous or skolemized.
>
> GK, correct me if I misunderstood.
>
> Jim
>
>
> On Wed, Jun 27, 2012 at 2:21 PM, Paul Groth <p.t.groth@vu.nl> wrote:
>
>> So the use case is the issue?
>>
>> I really don't get how the example breaks any semantics. Sorry...
>>
>> So I think that your approach to allowing a qualified specialization
>> would be fine with me especially if we add a inBundle predicate that
>> identifies a bundle. but Tim was really really against this because of the
>> increased number of triples.
>>
>> Paul
>>
>>
>> On Jun 27, 2012, at 19:48, Graham Klyne <graham.klyne@zoo.ox.ac.uk>
>> wrote:
>>
>> > On 27/06/2012 18:39, Paul Groth wrote:
>> >> Hi Graham
>> >>
>> >> These are two different urls so they identify different things.
>> >
>> > Not necessarily,  There is no unique-name assumption in RDF.  They
>> could denote
>> > the same thing.
>> >
>> >> The fact that we add some properties like bundle or specializationof
>> doesn't break anything. I can do that with any resource on the web, no?
>> >
>> > Adding the properties per se doesn't break anything, but when they are
>> presented
>> > as addressing a use-case that I don't believe can be addressed by RDF
>> semantics,
>> > they run the risk of encouraging people to creating RDF data that
>> doesn't mean
>> > what they think it means when interp[reted in accordance with RDF
>> semantics.
>> >
>> > #g
>> > --
>> >
>> >> Paul
>> >>
>> >> On Jun 27, 2012, at 19:09, Graham Klyne<graham.klyne@zoo.ox.ac.uk>
>> wrote:
>> >>
>> >>> On 27/06/2012 10:49, Luc Moreau wrote:
>> >>>> All,
>> >>>>
>> >>>> At the face to face meeting, we have agreed to rename
>> contextualization and mark
>> >>>> this feature
>> >>>> at risk. Tim, Stephan, Paul and I have worked a solution that we now
>> share with
>> >>>> the working group.
>> >>>
>> >>> I'm afraid I still have a problem with this.
>> >>>
>> >>> Considering your bundle tool:analysis01:
>> >>> [[
>> >>> bundle tool:analysis01
>> >>>     agent(tool:Bob-2011-11-16, [perf:rating="good"])
>> >>>     specializationOf(tool:Bob-2011-11-16, ex:Bob, ex:run1)
>> >>>
>> >>>     agent(tool:Bob-2011-11-17, [perf:rating="bad"])
>> >>>     specializationOf(tool:Bob-2011-11-17, ex:Bob, ex:run2)
>> >>> endBundle
>> >>> ]]
>> >>>
>> >>> The problem is that, if subject to RDF semantics for URI
>> interpretation, I can
>> >>> see no semantic distinction is possible between
>> >>>
>> >>>   tool:Bob-2011-11-16
>> >>> and
>> >>>   tool:Bob-2011-11-17
>> >>>
>> >>> I.e. they are both specializations of ex:Bob, and that is all we can
>> know about
>> >>> them, as (by the nature of the semantics of URI interpretation) the
>> denotation
>> >>> of ex:Bob that appears in ex:run1 is the same as the denotation of
>> ex:Bob that
>> >>> appears in ex:run2.
>> >>>
>> >>> ...
>> >>>
>> >>> I do, however, have a different compromise that provides a hook for
>> introducing
>> >>> possible semantics later, or in private implementations, without
>> sneaking in
>> >>> something that could well turn out to be incompatible with, or just
>> different
>> >>> than, what the RDF group may do for semantics of datasets.
>> >>>
>> >>> The hook is this: simply allow attributes for the specializationOf
>> relation, but
>> >>> don't define a specific attribute for bundle.  This would allow you
>> to do a
>> >>> private implementation of the scheme you describe, but would not
>> allow it to be
>> >>> mistaken for something that has standardized semantics.  As in:
>> >>>
>> >>>   specializationOf(tool:Bob-2011-11-17, ex:Bob,
>> >>>                    [myprivateattribute:bundle=ex:run2])
>> >>>
>> >>> ...
>> >>>
>> >>> In case you think I'm jumping at shadows here, I'll note that RDF has
>> been here
>> >>> before.  The original 1999 RDF specification described reification
>> without
>> >>> formal semantics.  Reification was intended to allow for capturing
>> this kind of
>> >>> information - i.e. to make assertions about context of use, etc - a
>> kind of
>> >>> proto-provenance, if you like.  But when the group came to define a
>> formal
>> >>> semantics for RDF, there were two possible, reasonable and
>> semantically
>> >>> incompatible approaches; looking at the way that reification was
>> being used "in
>> >>> the wild", it turned out that there was data out there that
>> corresponded to both
>> >>> of these (incompatible) approaches.  This was in the very early days
>> of the
>> >>> semantic web, so the harm done was quite limited.  I think a similar
>> mistake
>> >>> today would cause much greater harm.
>> >>>
>> >>> I think the appropriate way forward is to take this tool performance
>> analysis
>> >>> use-case to the RDF-PROV coordination group, and ask that it be
>> considered as
>> >>> input when defining semantics for RDF datasets.  I would expect that
>> whatever
>> >>> semantic structure they choose, it should be able to accommodate the
>> use-case.
>> >>> Then, we should be better placed to create an appropriate and
>> compatible
>> >>> contextualization semantics for provenance bundles.  But until then,
>> I think we
>> >>> invite problems by trying to create a standardized data model
>> structure without
>> >>> standardized RDF-compatible semantics to accommodate this use-case.
>> >>>
>> >>> #g
>> >>> --
>> >>>
>> >>> Tracker, this is ISSUE-385
>> >>>
>> >>> On 27/06/2012 10:49, Luc Moreau wrote:
>> >>>> All,
>> >>>>
>> >>>> At the face to face meeting, we have agreed to rename
>> contextualization and mark
>> >>>> this feature
>> >>>> at risk. Tim, Stephan, Paul and I have worked a solution that we now
>> share with
>> >>>> the working group.
>> >>>>
>> >>>> Given that contextualization was already defined as a kind of
>> specialization, we
>> >>>> now allow an optional
>> >>>> bundle argument in the specialization relation. (Hence, no need to
>> create a new
>> >>>> concept!)
>> >>>>
>> >>>> See section 5.5.1 in the current Editor's draft
>> >>>>
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#term-specialization
>> >>>>
>> >>>> Feedback welcome.
>> >>>>
>> >>>> Regards,
>> >>>> Luc
>> >>>>
>> >>>> PS. Tracker, this is ISSUE-385
>> >>>>
>> >>>
>> >>
>> >>
>>
>>
>
>
> --
> Jim McCusker
> Programmer Analyst
> Krauthammer Lab, Pathology Informatics
> Yale School of Medicine
> james.mccusker@yale.edu | (203) 785-6330
> http://krauthammerlab.med.yale.edu
>
> PhD Student
> Tetherless World Constellation
> Rensselaer Polytechnic Institute
> mccusj@cs.rpi.edu
> http://tw.rpi.edu
>
Received on Wednesday, 27 June 2012 22:01:44 UTC

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