Re: PROV-ISSUE-66 (is-execution-a-bob): Why is process execution not defined as a characterised entity? [Conceptual Model] from Satya Sahoo on 2011-08-02 (public-prov-wg@w3.org from August 2011)

From: Satya Sahoo <satya.sahoo@case.edu>
Date: Mon, 1 Aug 2011 20:33:05 -0400
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Cc: public-prov-wg@w3.org
Message-ID: <CAOMwk6wfbupmy0egFWOgVh+xesG+TX9=a+VUtJ7372g4vc36Yw@mail.gmail.com>
Hi Simon, Luc, and Jim,
I agree with Simon's initial point, which I was making when I raised the
issue, that our current definition of BOB as characterizable entity allowed
PE to be a subclass of BOB -hence the need to change the definition of BOB.

Going back Luc's initial point about perdurant and endurant - actually
continuant and occurrent (since we are talking about universals that have
instances [1]), BOB in our work refers to continuant and PE to occurrent (in
both cases may be in a less than direct manner).

Since the distinction between continuant and occurrent is well understood
and accepted by many knowledge representation communities (e.g. both BFO and
DOLCE upper level ontologies), I suggest that we reuse this in our work.

Since, we are voting to call BOB as entity (according to current voting
patterns), I propose the following modification of BFO definitions of
continuant and occurrent [2] for our purpose:
Continuant/BOB: A thing that exists in full at any time in which it exists
at all, persists through time while maintaining its identity and has no
temporal parts.
Occurrent/PE: A thing that has temporal parts and that happens, unfolds or
develops through time.

I suggest that we refer to both DOLCE and BFO documents to get further
details and background about the above definitions ([1] has good
explanation).

As Jim discusses, BOB and PE are related by the participation property
(which would make use and generation its sub-properties).

Thanks.

Best,
Satya

[1] DOLCE: http://www.springerlink.com/content/5p86jk323x0tjktc/fulltext.pdf
[2] BFO terms: www.ifomis.org/bfo/1.1


On Mon, Aug 1, 2011 at 7:13 PM, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:

> Hi Simon,
>
> Response interleaved.
>
>
> On 01/08/11 17:18, Simon Miles wrote:
>
>> Hi Luc, Jim,
>>
>> Luc:
>>
>>
>>> We still haven't defined process ordering, and I would argue that
>>> ... We haven't had time to define this in spec. Sorry.
>>>
>>>
>> OK. I'm not certain having a signal from one execution to another is
>> the same as one creating another, but am happy to leave this debate if
>> you think it is not for this draft.
>>
>>
>>
> Hopefully, we'll write something by end of the week.
> This said, I have looked at starting/ending process execution
> as control, rather than process ordering (a la opm:wasTriggeredBy).
>
>
>  But surely there still needs to be some resolution to the issue
>> itself? The model implies (or is at least very easy to read as
>> implying) that a PE is a kind of BOB, by the fact that a PE as defined
>> fits the definition of a BOB. But if this is not intended, then what
>> should the OWL file contain to reflect the model accurately? Again, I
>> believe this was Satya's point, but he should probably clarify
>> himself.
>>
>>
> Why not simply: BOB owl:isDisjointWith ProcessExecution?
>
> Luc
>
>
>  [ To justify the importance of clarifying this in the model, I was
>> working with someone last week who was using OPM and had expressed
>> things in their application as artifacts that I would intuitively
>> considered processes. They saw the final report on each process as
>> their only knowledge of it, and those reports are static, so the
>> processes were modelled as artifacts but with the names and reported
>> characteristics of the processes. ]
>>
>> Jim, if I understand your argument correctly, you are saying that:
>>  - we should redefine PE/BOB to ensure a PE is not a BOB
>>  - we should define a relation from a PE to its 'substrate(s)', which are
>> BOBs
>>  - describing the provenance of these substrates (along with
>> everything else PIL can already say) completes the description of the
>> provenance of a PE
>>
>> 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.
>>
>> 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<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<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<http://www.ecs.soton.ac.uk/~lavm>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> ______________________________**______________________________**__
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>>>>
>>>>
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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                     http://www.ecs.soton.ac.uk/~**lavm<http://www.ecs.soton.ac.uk/~lavm>
>>>>
>>>>
>>>>
>>>
>>>
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>>
>>
>>
>>
>
>
Received on Tuesday, 2 August 2011 00:33:36 UTC