- From: Timothy Lebo <lebot@rpi.edu>
- Date: Fri, 6 Jul 2012 13:13:16 -0400
- To: Paul Groth <p.t.groth@vu.nl>
- Cc: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, Provenance Working Group <public-prov-wg@w3.org>
On Jul 6, 2012, at 11:09 AM, Paul Groth wrote: > My suggestion would be to put this as an issue to be considered with > all the issues arising from last call. > I made ISSUE-447 for this thread. -Tim > I think as a process, we should try to collect these issues and then > see what we do about each. > > cheers > Paul > > On Fri, Jul 6, 2012 at 5:04 PM, Timothy Lebo <lebot@rpi.edu> wrote: >> Stian, >> >> (cc'ing our working group list instead of the comments list) >> >> On Jul 6, 2012, at 10:09 AM, Stian Soiland-Reyes wrote: >> >>> I would at least be very interested in defining activity composition >>> as part of PROV. >>> >>> I think as Tim points out there are many existing ways to model >>> composition, but I don't think that means that PROV should ignore >>> composition of activities and entities - it would be important to >>> understand that for the outcome of the ex:Project there were many >>> ex:MRIScannings - if we leave these to custom attributes, then those >>> are separate islands in PROV. >> >> As Paul mentions, heading down the path of composition leads to an abundance of details that would need to be considered, and is beyond the scope of our charter. >> For example, I imagine we'd want temporal constraints imposing that the start of a child must not precede the start of the parent, etc. >> That's a whole new area of the material that we have not addressed as a WG during its lifetime, and deserves more time than we can give it as things are finishing up. >> >> Regarding your "islands" comment, that is the nature of defining any model with any coherent scope. >> We've had the "island" argument for Dictionaries, and they ended up in a Note (with only Collection and hadMember surviving as a Rec). >> So, perhaps we respond to Satra's comment with a bare-bones activity composition? >> I'd like to point out that specialization already provides an orthogonal dimension similar to activity composition, but specialization is only among entities. >> Also, is there adequate prior art on activity composition and granularity management? From what I've seen, the community has only stabbed at different parts of the elephant. >> >>> >>> We did get rid of wasStartedByActivity for simplicity. Perhaps for >>> wasInformedBy we can suggest some subtypes like prov:WasPartOf ? >> >> Although wasPartOf may be a subtype of wasInformedBy from a workflow perspective, I think communication and part hood are orthogonal in general. >> So tucking it under there doesn't seem appropriate. >> >> Regards, >> Tim >> >> >>> >>> >>> >>> On Fri, Jul 6, 2012 at 2:14 PM, Paul Groth <p.t.groth@vu.nl> wrote: >>>> Hi Satra, >>>> >>>> Thanks for the question. We actually have had several people ask a >>>> similar question. So I'm also curious what the group will answer :-) >>>> >>>> For wasFollowedBy, we actually have the relation wasInformedBy which >>>> you can use for activity ordering. >>>> >>>> I think we were reticent to start defining the composition of >>>> activities because that could lead down the path of defining an entire >>>> workflow or programming language, which is not in our charter or >>>> something we would want to do. I guess the answer was that we were >>>> worried about feature creep. Do we stop at just composition or would >>>> other constructs be necessary? >>>> >>>> thanks >>>> Paul >>>> >>>> On Fri, Jul 6, 2012 at 2:45 PM, Satrajit Ghosh <satra@mit.edu> wrote: >>>>> hello, >>>>> >>>>> i was discussing this with luc and based on his feedback thought it might be >>>>> useful to bring this up on the list. >>>>> >>>>> ---- >>>>> question: >>>>> how do you encode that a certain activity "emailing a letter" happened >>>>> during another activity "a meeting"? >>>>> >>>>> for example we conduct research studies/projects. >>>>> >>>>> activity(p1, [prov:type='ex:Project']) >>>>> activity(p2, [prov:type='ex:MRIScanning', ex:session=1]) >>>>> activity(p3, [prov:type='ex:MRIScanning', ex:session=2]) >>>>> >>>>> how would i encode that this activity p2 and p3 were conducted during p1? >>>>> how would i encode p3 followed p2? >>>>> >>>>> >>>>> luc's response: >>>>> Regarding your question, there may be a few options: >>>>> you could add time information to your activities. This will help you >>>>> understand their ordering. >>>>> >>>>> Alternatively, if you want an explicit dependency in your graph, then p2 may >>>>> generate something >>>>> that starts p3, and/or is consumed by p3 >>>>> >>>>> Finally, prov doesn't have relations between activities, to express their >>>>> nesting, etc. It's important >>>>> but we felt this is not specific to provenance, but to process executions. >>>>> ---- >>>>> >>>>> it's the last point on this response that i was not completely sure about. >>>>> why "relations between activities" is "not specific to provenance, but to >>>>> process executions." >>>>> >>>>> in the above example, one could say: >>>>> >>>>> wasSubtaskOf(p2, p1) >>>>> wasSubtaskOf(p3, p1) >>>>> wasFollowedBy(p2, p3) >>>>> >>>>> any clarification as to why such relations would be outside the realm of >>>>> provenance would be much appreciated. >>>>> >>>>> cheers, >>>>> >>>>> satra >>>> >>> >>> >>> >>> -- >>> Stian Soiland-Reyes, myGrid team >>> School of Computer Science >>> The University of Manchester >>> >>> >> > > > > -- > -- > Dr. Paul Groth (p.t.groth@vu.nl) > http://www.few.vu.nl/~pgroth/ > Assistant Professor > Knowledge Representation & Reasoning Group > Artificial Intelligence Section > Department of Computer Science > VU University Amsterdam > >
Received on Friday, 6 July 2012 17:13:55 UTC