- From: Satya Sahoo <satya.sahoo@case.edu>
- Date: Wed, 27 Jun 2012 18:01:13 -0400
- 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>
- Message-ID: <CAOMwk6yAJr=jsAmZyeonWzxxABimm_wWqsMgd9iRJ2cAChDYCA@mail.gmail.com>
> > 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