- From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- Date: Wed, 27 Jun 2012 18:48:09 +0100
- To: Paul Groth <p.t.groth@vu.nl>
- CC: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, Provenance Working Group WG <public-prov-wg@w3.org>
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 17:49:22 UTC