- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Tue, 17 Jan 2012 11:30:09 +0000
- To: public-prov-wg@w3.org
Here is a suggestion: For every imprecise derivation, we can associate the time at which e2 is generated. Hence, wasDerivedFrom(e2,e1,t,attrs) is a shortcut for: wasDerivedFrom(e2,e1,attrs) wasGeneratedBy(e2,t) Note that this assumes that activity is not mentioned in generation record. This is outstanding ISSUE-205. Cheers, Luc On 01/17/2012 11:24 AM, Luc Moreau wrote: > Hi Paul, > > Still trying to tackle this outstanding issue. what are your views on > this last message? > > Thanks, > Luc > > On 11/30/2011 02:39 PM, Luc Moreau wrote: >> Hi Paul, >> >> Trying to come back to this issue, now that we have revised the >> notion of derivation. >> >> While I am sympathetic to the idea of "short-cuts" to facilitate >> life of asserters, >> I am also keen to stick to some (unwritten) design principles. >> >> 1. There should be one and only one place where a given piece of >> information can >> be placed in the data model. Failing to do so, then, asserters >> won't know where to >> assert information. Furthermore, the data model will have to >> specify what it means >> when places for a given piece of information contain different >> values. >> >> In this case, derivation time(=generation time) could be placed in >> a derivation and in >> a generation record. >> >> 2. Uniformity. If we make this time optional in derivation, we >> should also make it on >> "specializations" of derivation such as wasSummaryOf etc. >> We don't do it. >> >> Ultimately, writing a derivation time (=generation time) requires >> precision. >> We shouldn't do it with an imprecise record. In the new terminology, >> were you suggesting >> to do have this option in imprecise-1 records? imprecise-n? >> >> Luc >> >> On 11/11/2011 04:26 PM, Luc Moreau wrote: >>> Hi Paul, >>> Remember that the activity may have been a long running service, >>> which started well before the entity was used, >>> and vice-versa, it could have ended well after the other entity was >>> generated. >>> >>> Let us know what event you choose, and we'll encode this. >>> Luc >>> >>> On 11/11/2011 15:52, Paul Groth wrote: >>>> Hi Luc, >>>> >>>> Ok, I see what your asking. I think we can reuse the events. My >>>> general thought is that (at 10 am) applies to the activity (e.g. >>>> the anonymous activity that used the report). So that would map to >>>> either the start or end of the activity or both? >>>> >>>> I'm not sure what's nicest. >>>> >>>> Thanks, >>>> Paul >>>> >>>> Luc Moreau wrote: >>>>> Hi Paul, >>>>> >>>>> Comments interleaved. >>>>> >>>>> On 11/09/2011 08:53 AM, Paul Groth wrote: >>>>>> Hi Luc, >>>>>> >>>>>> For me this is about, saying the following: >>>>>> >>>>>> blogpost wasDerivedFrom Report at 10am Thursday >>>>> >>>>> What do you mean by this: blogpost was generated at 10am? >>>>> >>>>>> Sure there is some process there, there may be an interval. But I >>>>>> just >>>>>> don't want to assert all that information. >>>>> >>>>> I understand, but ultimately, I am trying to determine whether >>>>> there is >>>>> a new special event 'derivation' to which >>>>> time is associated with, or whether we can reuse generation/use >>>>> events >>>>> or start/end events. >>>>> >>>>>> Again, my fundamental thing is that I want to assert derivation >>>>>> chains >>>>>> without (knowingly) asserting anything about process. >>>>>> >>>>>> Maybe the point is I'm looking for a shortcut such that if I >>>>>> assert a >>>>>> time it automagically infers that the e2, and e1 are on the same >>>>>> time >>>>>> line using the same clock and are the same time? >>>>> >>>>> Inferring time line and same clock would be no good. >>>>> >>>>>> Does that make sense? >>>>>> >>>>> >>>>> I still need you to clarify the intended semantics, specifically, >>>>> what >>>>> notion of time you refer to. >>>>> Then, when it's decided, we can express the short cut. >>>>> >>>>> My take on it, in the above example, you refer to the blogpost >>>>> generation time. >>>>> >>>>>> Paul >>>>> >>>>> Luc >>>>>> Luc Moreau wrote: >>>>>>> Hi Paul, >>>>>>> >>>>>>> I'd like to come back to this issue, and see how we can solve it. >>>>>>> >>>>>>> The fully expanded notion of derivation, written >>>>>>> wasDerivedFrom(e2,e1,pe,q2,q1), >>>>>>> refers to the generation event for e2, and the use event for e1. >>>>>>> So, they form an "interval". If we have time information for >>>>>>> each of these events (and assuming a same clock), we can compute >>>>>>> the >>>>>>> duration >>>>>>> of this interval. >>>>>>> >>>>>>> So, the question is, do you really have a use case, where you >>>>>>> don't want >>>>>>> to assert the use/generation events (qualified usage/generation) >>>>>>> but >>>>>>> want >>>>>>> to express time? Can you explain it? >>>>>>> >>>>>>> My concern is that we are at risk of introducing two >>>>>>> placeholders for >>>>>>> the same time information >>>>>>> (in derivation or use/generation events). Two placeholders for >>>>>>> time may >>>>>>> result in inconsistent >>>>>>> information. >>>>>>> >>>>>>> Luc >>>>>>> >>>>>>> >>>>>>> On 07/23/2011 04:46 PM, Provenance Working Group Issue Tracker >>>>>>> wrote: >>>>>>>> PROV-ISSUE-43 (derivation-time): Deriviation should have >>>>>>>> associated >>>>>>>> time [Conceptual Model] >>>>>>>> >>>>>>>> http://www.w3.org/2011/prov/track/issues/43 >>>>>>>> >>>>>>>> Raised by: Paul Groth >>>>>>>> On product: Conceptual Model >>>>>>>> >>>>>>>> Other relationships have time associated with them (e.g. use, >>>>>>>> generation, control) >>>>>>>> >>>>>>>> There is no optional time associated with derivation. >>>>>>>> >>>>>>>> Suggested resolution is to add the following to the definition of >>>>>>>> isDerivedFrom: >>>>>>>> >>>>>>>> - May contain a "derived from time" t, the time or time intervals >>>>>>>> when b1 was derived from b2 >>>>>>>> >>>>>>>> Example: >>>>>>>> isDerivedFrom(b1,b2, t) >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>> >>>> >>> >> > -- 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, 17 January 2012 11:30:42 UTC