RE: PROV-ISSUE-66 (is-execution-a-bob): Why is process execution not defined as a characterised entity? [Conceptual Model]

> 
> Jim, if I understand your argument correctly, you are saying that:
>  - we should redefine PE/BOB to ensure a PE is not a BOB
~Yes - I think this is the current definition's intention, so this would be a rewording to avoid a PE=Bob interpretation

>  - we should define a relation from a PE to its 'substrate(s)', which are BOBs
I would like to see this as the definition of participatesIn - participation is listed but the definition is not in the model doc yet and is afaik still being discussed. I'm not sure that we should use the language of a PE having a 'substrate' per se (which comes from the perdurant/occurent literature), but I think our more general notion that participation means somehow contributing to the process versus being an input/output of the process is consistent. Some of the other proposals for participation (e.g. it means used or generated by as well), would probably be inconsistent. Having control be a type of participation, such that agents would be part of the 'substrate' for a process along with physical substrates (e.g. the oven and cake pan in baking), would be consistent.

>  - describing the provenance of these substrates (along with everything else
> PIL can already say) completes the description of the provenance of a PE
I think so. Flipping this, if it can't, one would have to identify something that could affect a PE that is neither an input, nor a substrate, nor the recipe (or less strongly that there's something that could not be modeled in these ways).

> 
> Is that correct? If so, I can buy that, but I'm not yet clear what that would look
> like in the model document, or if you are saying it is already as such in the
> document.

Given an consistent definition of participation, I think this would be in the model and in the doc already. 
A thunderstorm PE (thunderstorm is a classic perdurant example) that used a' house' and generated a 'pile of wood' might be controlled by a 'butterfly', subject to the laws of nature as encoded in a recipe link, and involve the participation of clouds/moisture, air, ground terrain, sunshine, etc. I think if I give you the history of all of those (the laws of nature hopefully being unchanging), I think you can answer any queries you have about why this storm happened the way it did and hence you have the full provenance. (Modulo not having all the information - i.e. given that weather is chaotic, not knowing the butterfly's exact position and flapping history would limit how far you could go in seeing of the outcome was consistent with/predictable given the provenance.)

 Jim 


> 
> Thanks,
> Simon
> 
> On 1 August 2011 16:38, Myers, Jim <MYERSJ4@rpi.edu> wrote:
> > While I suspect that the potential symmetry that Simon is identifying
> > is 'there', I would argue against making PE = Bob (or making them
> > subclasses of a common ancestor) from two angles:
> >
> > The most compelling to me is just that I cannot see how we're going to
> > explain the model if we argue that what people typically think of as
> > objects and what they typical call processes are really not so
> > distinguishable. As I'll suggest below, I think we have ways to
> > address Simon's use cases if we have IVPof (and maybe participates)
> > and I'm hopeful we can argue for them without resorting to
> > endurant/perdurant arguments. (If we did make them the same, or
> > subclasses of the same thing (and we can find the Bob and PE that
> > correspond via some
> > relation(s) in the model) , we would be adding a duplicate mechanism
> > to model their provenance...).
> >
> >
> > For those who want to do that, here's my take on the mapping: I think
> > we primarily have an endurant(Bob) - perdurant (PE) model - that's the
> > used/generatedby core of the model. In the spirit of "The Water Falls
> > But The Waterfall Does Not Fall", by Galton and Mizoguchi, though, pil
> > recognizes that things we think of as endurants can also have a
> > perdurant aspect when we consider other processes. An endurant egg
> > that goes into a cake baking process (endurant in the sense that at
> > each instant in time, it is indeed an egg), is also participating in a
> > 'warming egg' process (perdurant in the sense that at no point in time
> > is the egg actually warming, participates implying that the endurant
> > egg is part of the substrate for the perdurant process). To model
> > this, we have IVPof which allows us to model the warming egg by
> > talking about the cold egg (endurant), the heating process
> > (perdurant), and the warm egg (endurant). What we don't have in the model
> is the 'warming egg'
> > directly - no way to say energy went into a 'warming egg' without
> > identifying the 'heating process' separately and saying energy and the
> > 'cold egg' were inputs.
> >
> > Philosophy aside, I think it is true that IVPof and participates (in
> > the sense used here - not sure where the group debate has settled on
> > pil:participates) allows us to cover all of the use cases where you
> > might want to talk about the perdurant aspects of an endurant Bob or
> > the endurant aspects of a perdurant PE. A PE's provenance would be
> > complete if one described the provenance of all inputs (used) and the
> > provenance of all Bobs that 'participate in'/are the substrate for the
> > PE. A Bob's provenance would be complete if one described the PE that
> > generated it and all of the PEs it had "participated in".
> >
> > So - hopefully the discussion here helps. If not, my basic sense is
> > that
> >
> >
> >
> >> -----Original Message-----
> >> From: public-prov-wg-request@w3.org [mailto:public-prov-wg-
> >> request@w3.org] On Behalf Of Luc Moreau
> >> Sent: Monday, August 01, 2011 6:50 AM
> >> To: public-prov-wg@w3.org
> >> Subject: Re: PROV-ISSUE-66 (is-execution-a-bob): Why is process
> > execution
> >> not defined as a characterised entity? [Conceptual Model]
> >>
> >> Hi Simon,
> >>
> >> While I mentioned, endurant/perdurant, I was using them for
> >> intuition,
> > and
> >> didn't mean to formally introduce them in the definition.
> >> You may be right, a BOB with temperature changing constantly, may not
> > fit
> >> the endurant/perdurant distinction. But I am not expert in this
> > ontology.
> >>
> >> But, I don't see why this makes a case for PE=BOB. What use case do
> > you try
> >> to resolve by merging the two concepts?  Its major downside is the
> > unknown
> >> meaning of using/generating a process execution.  It seems also to
> >> mix use/generation/start/end.
> >>
> >> I see a process execution as a set of events using/generating BOBs,
> > and
> >> temporally delimited by a start and end event.  This set of event is
> > said  by
> >> an asserter to be an identifiable activity.
> >> This activity has an "effect" on the world, by all the BOBs it
> > generates.
> >>
> >> So can you identify an example that we can't model with  PE<>BOB but
> > can
> >> with PE=BOB?
> >>
> >> Luc
> >>
> >> On 08/01/2011 11:09 AM, Simon Miles wrote:
> >> > Hi Luc,
> >> >
> >> > OK, I believe I understand your intuition, but would argue:
> >> >
> >> > 1. A process execution currently fits the definition of a BOB, as
> >> > it has assertable characteristics, is identifiable, and is an
> >> > entity, i.e. bounded.
> >> >
> >> > 2. I was not clear we wanted to restrict BOBs to endurants. For
> >> > example, at the F2F1, Tim raised the case of expressing that
> > something
> >> > changed temperature by 10 degrees (and why), without asserting what
> >> > the start and end temperatures were. If I remember correctly, you
> > and
> >> > I argued that the temperature change could be seen as an
> >> > (invariant) attribute of a BOB, because BOBs are not necessarily
> instantaneous.
> >> > And if I understand endurants and perdurants correctly, I think the
> >> > change is a perdurant because at any moment, the change itself is
> > not
> >> > apparent.
> >> >
> >> > Intuitively, it seems reasonable that a process execution is
> > something
> >> > you can ask the provenance of ("why did this execution occur as it
> >> > did?"). This might or might not be fully answered by saying what
> >> > the execution used, who it was controlled by, when it started, and
> >> > what recipe it followed.
> >> >
> >> > I recognise that it makes things complicated, in that a process
> >> > execution (as a BOB) could be "generated" or "used" by another
> >> > execution, but perhaps this is what we mean by the "ordering of
> >> > processes" concept anyway. The existing definition "Generation
> >> > represents the creation of a new characterized entity by an
> > activity.
> >> > This characterized entity did not exist before creation." seems to
> > fit
> >> > the notion of one process starting another one quite nicely.
> >> >
> >> > To be more constructive, here's my counter-proposal.
> >> >
> >> > * We add "characterized entity" to the process execution
> >> > definition, e.g. "A process execution represents an activity which
> >> > performs a piece of work. An activity is a kind of identifiable
> >> > characterized entity."
> >> >
> >> > No other change seems necessary, though some explanation of the
> >> > consequences may be needed. We might then have also covered
> > "ordering
> >> > of processes", at least in a causal sense (temporal ordering is
> >> > different).
> >> >
> >> > Thanks,
> >> > Simon
> >> >
> >> > On 1 August 2011 09:14, Luc
> Moreau<L.Moreau@ecs.soton.ac.uk>  wrote:
> >> >
> >> >> Hi Simon,
> >> >>
> >> >> To me, process executions are the "verbs", whereas BOBs are the
> >> >> "nouns", and therefore belong to different categories.
> >> >>
> >> >> Several people have also mentioned they relate to
> > perdurant/endurant
> >> >> in formal ontologies.
> >> >>
> >> >> Being identifiable is therefore not the key characteristic!
> >> >>
> >> >> Regards,
> >> >> Luc
> >> >>
> >> >>
> >> >> PS. In a separate thread, you mentioned that IVPof could be used
> > for
> >> >> process executions.
> >> >>     This may make sense, but in that case we simply need to change
> >> >> the signature of IVP of:
> >> >>          BOB x BOB   U   PE x PE
> >> >>
> >> >>
> >> >>
> >> >> On 07/29/2011 05:22 PM, Provenance Working Group Issue Tracker
> >> wrote:
> >> >>
> >> >>> PROV-ISSUE-66 (is-execution-a-bob): Why is process execution not
> >> >>> defined as a characterised entity? [Conceptual Model]
> >> >>>
> >> >>> http://www.w3.org/2011/prov/track/issues/66
> >> >>>
> >> >>> Raised by: Simon Miles
> >> >>> On product: Conceptual Model
> >> >>>
> >> >>> This was mentioned by Satya in the call, but I can't see it
> >> >>> having
> > been
> >> raised as an issue yet.
> >> >>>
> >> >>> As process executions are identified and may have attributes,
> > including
> >> start and end time, are they kinds of characterised entities,
> > similarly to
> >> agent? If not, why not?
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >> --
> >> >> 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
> >> >>
> >> >>
> >> >>
> >> >>
> >>
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> >> >
> >>
> >> --
> >> 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
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> >>
> >
> >
> >
> >
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> 
> --
> Dr Simon Miles
> Lecturer, Department of Informatics
> Kings College London, WC2R 2LS, UK
> +44 (0)20 7848 1166

Received on Monday, 1 August 2011 16:50:20 UTC