- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Tue, 06 Dec 2011 17:39:44 +0000
- To: public-prov-wg@w3.org
Hi Paul, Yes, that's what the group wanted, I believe. Luc On 12/06/2011 05:35 PM, Paul Groth wrote: > Hi Luc, > > Hmm, I think I remember this now..... so everything can be an entity > record as soon as you type it as such. > > For example if I have a webpage: > > http://www.example.com/webpage > > It becomes an entity record, as soon as I do: > > entity(http://www.example.com/webpage, []) > > Is that a correct interpretation? > > Paul > > > > > Luc Moreau wrote: >> Hi Paul, >> >> So, OK, we could mint identifiers for entity record >> >> entity(<a minted identifier here>, [ex:param="a", >> ex:port="foo"]) >> >> (Which by the way is what OPM does.) >> >> How do you refer to the entity now? We don't know what this record is >> about. >> >> Luc >> >> On 12/06/2011 05:11 PM, Paul Groth wrote: >>> So I always thought that you could mint identifiers for entity records >>> but you didn't have to and we supported that. >>> >>> But maybe that's my head inserting text where it shouldn't have >>> been.... >>> >>> Paul >>> >>> Luc Moreau wrote: >>>> ... the conclusion issue ;-) >>>> >>>> No, we have no formal decision on this. >>>> >>>> We wrote this in the prov-dm document a long time ago (before >>>> fpwd), and >>>> we have >>>> been refining it over time. >>>> >>>> I think it's an inevitable consequence of two key decisions: >>>> - distinguishing entities (in the world) from entity records (in the >>>> provenance) >>>> - not mandating the minting of new URIs for entity records >>>> (no formal decision on this, but I think we have support for >>>> it, since >>>> we want to minimize the effort to generate provenance) >>>> >>>> Luc >>>> >>>> >>>> On 12/06/2011 04:56 PM, Paul Groth wrote: >>>>> Hi Luc, >>>>> >>>>> Do you have a pointer to wear we reached the consensus about the dual >>>>> role of identifiers? >>>>> >>>>> Thanks, >>>>> Paul >>>>> >>>>> Provenance Working Group Issue Tracker wrote: >>>>>> PROV-ISSUE-183 (prov-dm-identifiers): identifiers in prov-dm >>>>>> [prov-dm] >>>>>> >>>>>> http://www.w3.org/2011/prov/track/issues/183 >>>>>> >>>>>> Raised by: Luc Moreau On product: prov-dm >>>>>> >>>>>> >>>>>> Hi, >>>>>> >>>>>> It think that it is now time to have a proper debate about >>>>>> identifiers in prov-dm since comments are regularly expressed about >>>>>> them. I have raised this issue about this topic so that we can track >>>>>> the conversation properly. Our hope is to reach consensus on this >>>>>> topic by the time of the third working draft. >>>>>> >>>>>> First, in the fpwd, there was a mention of "qualified identifier" >>>>>> (appearing in a note see [1]). We have removed this term from the >>>>>> second working draft. >>>>>> >>>>>> Second, the complementarity record now explicitly allows for linking >>>>>> entity records across accounts. Its syntax allows for two >>>>>> accounts to >>>>>> be named. >>>>>> >>>>>> Third, identifiers for entities in prov-dm have a dual role [3]. An >>>>>> entity has got an id (typically given by an application). An entity >>>>>> record --- i.e. what we say about an entity in a provenance record >>>>>> --- also has an id. There is a consensus that we shouldn't mint >>>>>> identifiers for provenance records. Hence, the identifier of the >>>>>> entity record is defined to be the same as the identifier of the >>>>>> entity. >>>>>> >>>>>> The consequence of this is that two entity records in different >>>>>> accounts may have the same identifier: they may say different things >>>>>> about the same entity. For example, the document ex:doc was >>>>>> generated by latex in account1, while in account 2, ex:doc is >>>>>> described to be the result of a survey of a field by different >>>>>> authors. >>>>>> >>>>>> This explains why we needed the complementarity record to name the >>>>>> accounts as well. This assumes that account names need to be named >>>>>> uniquely (see [4]). >>>>>> >>>>>> So, entity records identifiers are scoped to accounts. Note, I said >>>>>> entity *records*, not entities. Hence, we are not breaking the >>>>>> semantic web approach: an entity is a resource and is denoted by a >>>>>> URI, and this remains true in all accounts. (I guess that from a >>>>>> semantic web perspective we are not looking at a provenance >>>>>> record as >>>>>> resource, since we don't have a global URI to name it.) Finally, we >>>>>> allow for accounts to be nested hierarchically; this fits nicely >>>>>> with >>>>>> abstraction in provenance records. Again, see [4]. >>>>>> >>>>>> Can you express your views about this approach, as currently defined >>>>>> in the second draft of prov-dm? >>>>>> >>>>>> Thanks, Luc >>>>>> >>>>>> [1] >>>>>> http://www.w3.org/TR/2011/WD-prov-dm-20111018/#expression-identifier >>>>>> [2] >>>>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/ProvenanceModel.html#record-complement-of >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>> [3] >>>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/ProvenanceModel.html#record-Entity >>>>> >>>>> >>>>> >>>>>> [4] >>>>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/ProvenanceModel.html#record-Account >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >> > -- Professor Luc Moreau Electronics and Computer Science tel: +44 23 8059 4487 University of Southampton fax: +44 23 8059 2865 Southampton SO17 1BJ email: l.moreau@ecs.soton.ac.uk United Kingdom http://www.ecs.soton.ac.uk/~lavm
Received on Tuesday, 6 December 2011 17:40:26 UTC