- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Wed, 27 Jun 2012 22:19:15 +0100
- To: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- CC: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Graham, I don't understand what you are saying here. Please see below. On 27/06/12 18:09, Graham Klyne 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. > Are you trying to say that if specializationOf(luc-in-boston,luc) specializationOf(luc-in-soton,luc) You cannot see any semantic distinction between luc-in-boston and luc-in-soton????? Surely, there is a difference! Likewise, tool:Bob-2011-11-16 and tool:Bob-2011-11-17 can be distinguished by the additional aspect they present (bundle ex:run1 or bundle ex:run2). In this example, we have three different identifiers ex:Bob tool:Bob-2011-11-16 tool:Bob-2011-11-17 each with a single denotation: i.e. no denotation that is context specific. I don't see what the issue is. Luc Luc > ... > > 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 21:19:44 UTC