- From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- Date: Fri, 22 Jun 2012 15:33:03 +0100
- To: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- CC: Provenance Working Group WG <public-prov-wg@w3.org>
Luc, I can't manage the detailed context(sic) of this discussion and example when it comes round every few days -- but I do believe that the contextualization relation is potentially dangerous. As far as I can tell it has NO semantics that distinguish it from specializationOf, yet I believe it encourages users to read into it uses that could violate the semantics of RDF URI usage. Thus, my immediate question is this. What inferences are possible using contextualizationOf: A contextualizationOf(e1, e2, b) |- B that are not also valid inferences using specializationOf A specializationOf(e1, e2) |- B ? I can't see any. In the absence of such, I can't see any valid reason for including contextualizationOf. And in the absence of such, I can't see the formal basis for your (implied) claim that contextualizationOf does identify the bundle in which ex:Bob occurred. I believe this is an area in which we really *need* formalization and rigour. Part of the reason that I'm so wary of this particular relation is that I think it usurps a part of semantic web technology that is being defined by the RDF working group ("named graphs", datasets and associated semantics). As such, I think the whole discussion about this should be conducted in the provenance+RDF coordination group. #g -- On 21/06/2012 13:43, Luc Moreau wrote: > Hi Graham, > > It is on purpose that we didn't define context. In the WG there is a precedent > of not defining > terms. To name a few: thing, aspect, act upon/with, bear responsibility, goals, > steps, assignment, ... > So the word 'context' is to be understood with its informal meaning, .... like > 'context' already > used in the definition of association [1]. > > As far as your response to Tim is concerned, of course, we > can say that if > tool:Bob_as_in_run1 prov:contextualizationOf ex:Bob > then > tool:Bob_as_in_run1 prov:specializationOf ex:Bob > given that contextualizationOf is defined as a subproperty of specializationOf. > > But your solution fails to identify the bundle in which ex:Bob occurred, which > led to the poor rating. > Regards, > Luc > > [1] > http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#concept-activityAssociation > > > On 15/06/2012 16:32, Graham Klyne wrote: >> This is my attempt to respond to ACTION-92. >> >> On 14/06/2012 23:07, Luc Moreau wrote: >> > In your absence, we assigned ACTION-92 to you. >> > Can you provide an example of contextualization you think >> > may break rdf semantics? >> >> This is hard to do without a complete formal description of what >> contextualization actually means. >> >> I did reply [1] to Tim's comment, and the reference to the example in the wiki. >> I would adjust my earlier comment to say something like this: I cannot see >> how contextualization can be anything but vacuous without violating RDF >> semantics; i.e. how it actually expresses anything that cannot be expressed >> without it. >> >> I've studied the description of contextualization in DM >> (http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#term-contextualization), >> >> and when I dig in to it I find I can't make any sense of what it is saying. >> >> As it stands, the notion of context is undefined, so I am unable to interpret >> statements like "A bundle's descriptions provide a context in which to interpret >> an entity in a domain-specific manner". What is this "context"? When I look to >> the definition of "bundle", I see "A bundle is a named set of provenance >> descriptions ...". There's nothing here about defining or providing a >> "context". So this notion of context is being introduced without any grounding >> or basis for understanding what it means. >> >> #g >> -- >> >> [1] http://lists.w3.org/Archives/Public/public-prov-wg/2012Jun/0310.html >> >> >> On 14/06/2012 23:07, Luc Moreau wrote: >>> Graham, >>> In your absence, we assigned ACTION-92 to you. >>> Can you provide an example of contextualization you think >>> may break rdf semantics? >>> Thanks, >>> Luc >>> >>> PS. Tracker, this is ISSUE-385 >>> >>> On 14/06/12 23:04, Luc Moreau wrote: >>>> Dear all, >>>> >>>> Minutes of todays's teleconference can be found at >>>> http://www.w3.org/2011/prov/meeting/2012-06-14 >>>> Thanks to Paolo for scribing. >>>> Regards, >>>> Luc >
Received on Friday, 22 June 2012 15:31:27 UTC