- From: Graham Klyne <GK@ninebynine.org>
- Date: Fri, 05 Aug 2011 08:12:12 +0100
- To: Paulo Pinheiro da Silva <paulo@utep.edu>
- CC: public-prov-wg@w3.org
Good point here, I think. Given that a process execution *has happened* or *has been observed* in some context... #g -- Paulo Pinheiro da Silva wrote: > Hi Luc, > > I would say that the thing that is deterministic or not is the recipe of > the process and neither the process execution or the process itself. For > example, a recipe can be deductive or inductive. > > It is a dangerous proposition to allowing process executions to be > labeled as deterministic or non-deterministic. For instance, let say > that one process is defined by a deductive recipe. This means that every > execution of this process needs to be deterministic. However, we cannot > prevent one execution of a process A to be deterministic and another > execution of A to be non-deterministic if we allow the representation to > accommodate such inconsistencies. > > Many thanks, > Paulo. > > > On 8/5/2011 12:42 AM, Luc Moreau wrote: >> >> Hi Jim and Reza, >> >> Jim's assumption is right. >> I am happy to mention (non)-determinism for PEs. >> >> Regards, >> Luc >> >> On 05/08/11 01:51, Reza B'Far wrote: >>> Makes sense. >>> >>> So, I suggest that we at least document that PE can be deterministic >>> or non-deterministic (both) so that it's not assumed that it is >>> deterministic... unless the majority here think this is obviated. >>> >>> On 8/4/11 5:42 PM, Myers, Jim wrote: >>>> I assume (always a bad idea :-)) that Luc means replay as in starting >>>> from the same input and running the same PE and checking to see if >>>> you get the same output. A lossy process would not be a problem since >>>> you have the original input, assuming you still have access. If the >>>> PE changes the image by rewriting the file, you’d at least have Bobs >>>> representing the file before and after and would know that you need >>>> access to the before-content to do replay. (Whether you have that >>>> version/back-up copy is out of scope). >>>> >>>> Another interesting replay question is if the PE is random/stochastic >>>> - a replay would not give the same result, but many replays would >>>> have some statistical relationship to each other. In either case, I >>>> think the provenance role is just to point to the Bobs and the PE so >>>> if you have access to the Bobs and understand what the PE is doing, >>>> you could try to replay. Going beyond that is probably out of scope... >>>> >>>> Jim >>>> >>>>> -----Original Message----- >>>>> From: public-prov-wg-request@w3.org [mailto:public-prov-wg- >>>>> request@w3.org] On Behalf Of Reza B'Far >>>>> Sent: Thursday, August 04, 2011 7:40 PM >>>>> To: public-prov-wg@w3.org >>>>> Subject: Re: PROV-ISSUE-26 (uses and generates questions): How can >>>>> one figure >>>>> out the provenance of a given entity? >>>>> >>>>> Luc - >>>>> >>>>> You mention "you may want to replay the execution...". Question >>>>> (and I hope >>>>> I'm not missing this conversation on a different thread) - >>>>> >>>>> Is Process Execution always lossless and linear in time? In other >>>>> words, is replay >>>>> always possible? (for example, can image compression be a process >>>>> execution >>>>> since the compression may be lossy?) Either way, I think this is >>>>> important to >>>>> articulate since it'll have ramifications on how inference engines >>>>> decide >>>>> whether it's possible to "replay" and if the "replay" is exact or >>>>> approximate. >>>>> >>>>> Hope the question is not nonsensical. >>>>> >>>>> On 8/4/11 4:16 PM, Luc Moreau wrote: >>>>>> Hi Paulo, >>>>>> >>>>>> Using the notation we have introduced in the provenance model, >>>>>> this is >>>>>> writen >>>>>> >>>>>> >>>>>> uses(pe, a, r_a) >>>>>> uses(pe, b, r_b) >>>>>> isGeneratedBy(c,pe,r_c) >>>>>> isDerivedFrom(c,a) >>>>>> >>>>>> where a,b,c are entities, pe a process execution and r_a, r_b, r_c >>>>>> roles. >>>>>> >>>>>> To try and answer your questions: >>>>>> - if something is wrong about c, you may want to inspect pe, and >>>>>> hopefully >>>>>> there are assertions about pe (not in this excerpt) which may be >>>>>> useful >>>>>> >>>>>> - you may want to replay the execution, and so having a and b, and >>>>>> knowing >>>>> which >>>>>> process definition underping pe, may help you verify the result. >>>>>> >>>>>> - I assume you mean can we infer that c was derived by the process >>>>>> execution >>>>>> >>>>>> Yes, this is explained in the document, and further refine in >>>>>> the >>>>>> soon-to-be-released new version. >>>>>> Only one pe can generate c (in one account). >>>>>> And from a derivation from c to a, one can infer the >>>>>> existence of >>>>>> a pe which generated c and used a. >>>>>> >>>>>> I hope it helps, >>>>>> Cheers, >>>>>> Luc >>>>>> >>>>>> On 07/07/11 15:50, Provenance Working Group Issue Tracker wrote: >>>>>>> PROV-ISSUE-26 (uses and generates questions): How can one figure out >>>>>>> the provenance of a given entity? >>>>>>> >>>>>>> http://www.w3.org/2011/prov/track/issues/26 >>>>>>> >>>>>>> Raised by: Paulo Pinheiro da Silva >>>>>>> On product: >>>>>>> >>>>>>> Context: >>>>>>> 1. P uses A >>>>>>> 2. P uses B >>>>>>> 3. P generates C >>>>>>> 4. C derived from A >>>>>>> >>>>>>> If the provenance of C is the concern of a user of C (as opposed to >>>>>>> the provenance of a process that generates C), one may have the >>>>>>> following >>>>> questions: >>>>>>> 1) What the “uses” and “generates” relationships are adding to one’s >>>>>>> understanding of C if something is wrong with C? >>>>>>> 2) Can we infer that A was derived by the execution of process P? >>>>>>> How? >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>> >> > > >
Received on Friday, 5 August 2011 07:13:01 UTC