- From: Paul Groth <p.t.groth@vu.nl>
- Date: Wed, 27 Jun 2012 20:21:32 +0200
- To: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- CC: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, Provenance Working Group WG <public-prov-wg@w3.org>
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 >>>> >>> >> >>
Received on Wednesday, 27 June 2012 18:21:56 UTC