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Re: smaller example

From: Simon Miles <simon.miles@kcl.ac.uk>
Date: Fri, 17 Jun 2011 11:52:43 +0100
Message-ID: <BANLkTimjnWV4fYghj-hcrD84P92ytFWVgA@mail.gmail.com>
To: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Jim,

I think I agree with your general argument against unification, and
I'm also aware that within the limited time of the WG, it is
preferable to err towards the set of concepts originally envisaged
unless we find that they really get in the way of expressing what
needs to be expressed (as we had with the exclusion of a "invariant
view of" relation).

But I do think it would be genuinely useful to allow us to
assert/query the provenance of executions, not just
data/objects/entities. For example, I would like to ask "What led to
this download action being performed?", separately from asking "What
is the history of the downloaded data?", e.g. I believe a trojan horse
might be downloading things behind my back, and the downloaded data
has since been deleted but a log of the download action allows me to
refer to it.

I wonder if we could not have the following compromise (which may be
what you were implying):

We still have "executions" controlled by "agents" using and generating
"entities", as stated in the charter. But we also have a more general
concept, X, which is a generalisation of "execution", "agent" and
"entity", and any other category of X common enough to be worth giving
a name to. To account for the overlap you describe, the categories
above do not have to be mutually exclusive (e.g. something could be an
execution and an agent if one choose to model it as such).

X would then correspond to the "thing" in the IVP definition, i.e. it
is something that we could assert the provenance of. As a name for X,
I suggest the term "thing" is not ideal, as it implies an entity not a
process execution, as well as clashing with owl:Thing seems more
general than we want. I personally like the term "occurrence".

Does this make sense, or is it overcomplicating matters?

Thanks,
Simon

On 16 June 2011 19:06, Myers, Jim <MYERSJ4@rpi.edu> wrote:
>
>> Just to note, wouldn't a process execution fit the definition of 'thing'? A process
>> execution can have an identity, is invariant at least with regards to that identity
>> (and maybe other things like its configuration or location), and is clearly mutable
>> in other regards.
>> I've no problem with a process execution being a thing if that is intended (a
>> process execution does have a provenance), but it might have implications for
>> which term we use in place of 'thing'.
>
> I think this is closely tied to the definition of agency - we're saying clouds participate in/control/affect  a storm rather than clouds/storm are a mutable thing/process execution. My guess is that the latter model could be made to work, but will be harder to explain and while it probably would be more powerful/remove some paradoxes of agents, I'm not sure it's worth it. I'm acutely aware that this is a slippery slope if we accept immutable and mutable thing to not be different classes - it is also more complex and more powerful than a two class model, so why not go the next step? The only difference is I think we have more use cases where being able to integrate the immutable/mutable perspectives is useful. My guess is that if we formulated some of the things we really want to say about agents (human agent and oven-as-agent), unifying thing and process execution might help, but I haven't thought it through and doubt I/we can explain it well enough to justify it as the PIL model. (Said differently, I see that we'll be dealing with ontologies for things like files that consider them mutable and immutable - I'm not sure there are many ontologies we're going to hit where one considers something a thing and the other considers it a process. Perhaps that's incorrect...)
>
> Fascinating, brain bending stuff...
> Cheers,
>  Jim
>>
>> Thanks,
>> Simon
>>
>> On 14 June 2011 10:53, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:
>> > Hi Simon,
>> >
>> > I think we concur. I have adapted the example taking into account the
>> > terminology we defined with Jim yesterday. [1]
>> >
>> > It would be nice to get feedback from the working group, since we may
>> > want to reach agreement on Thursday.
>> >
>> > [1]
>> > http://www.w3.org/2011/prov/wiki/ConceptInvariantViewOnThing#Definitio
>> > n_by_Jim_and_Luc_v2_.28in_progress.29
>> >
>> > Cheers,
>> > Luc
>> >
>> > On 06/13/2011 02:51 PM, Simon Miles wrote:
>> >> Luc,
>> >>
>> >> I think the example is helpful, and I suggest the discussion at the
>> >> end suggests that "invariant view or perspective on a thing" is not
>> >> quite right. All of i0, i1, i2, i3, i4 and i5 are more obviously
>> >> things than views: a file, or a file with some content, or the
>> >> content of a message.
>> >>
>> >> Instead, I suggest we mean "thing which is invariant from some
>> >> perspective", i.e. what we are talking about when referring to i0-i5
>> >> is the thing, not the view.
>> >>
>> >> They are all invariant in some way. For i1 to i5 they are invariant
>> >> from the perspective of their content, at very least. For i0, it is
>> >> invariant from the perspective of its identity, i.e. the reason why
>> >> we talk about i0 as a thing at all is that it is consistently
>> >> (invariantly) considered the same file even if its contents are
>> >> changed.
>> >>
>> >> I suggest i0 can be included in the Mapping as follows:
>> >> "We have some Abstractions I ->  I:
>> >> i1 ->  i0
>> >> i2 ->  i0
>> >> i3 ->  i0"
>> >> (meaning the abstraction of i1 is i0 etc.) Jim used the term
>> >> "abstraction" in his proposal for "resource" definition, but other
>> >> terms may be as good.
>> >>
>> >> Thanks,
>> >> Simon
>> >>
>> >> On 13 June 2011 10:37, Luc Moreau<L.Moreau@ecs.soton.ac.uk>  wrote:
>> >>
>> >>> Dear all,
>> >>>
>> >>> PROV-ISSUE-1
>> >>> PROV-ISSUE-8
>> >>> PROV-ISSUE-19
>> >>>
>> >>> On June 7th [1], we agreed on "In a first instance, to define the
>> >>> necessary concepts that allow us  to express the provenance of an
>> >>> invariant view or perspective on a thing".
>> >>> Putting this in practice turns out to be difficult.
>> >>>
>> >>> While the egg example is interesting, the scenario seems to evolve
>> >>> all the time. Also, I thought that, in a first instance, we may want
>> >>> to look at things that are digital, before seeing how our ideas
>> >>> extend to the non-digital world.
>> >>>
>> >>> Obviously, we have our data journalism example, but we seem to
>> >>> ignore. I think that we ignore it because:
>> >>> - it does not focus on changing things
>> >>> - it is not precise about how information is published/access,
>> >>> - it is quite long
>> >>> (I liked what Simon proposed for this example [2] and this inspired
>> >>> me here)
>> >>>
>> >>>
>> >>> To unblock the situation, I have:
>> >>> - drafted a smaller example [3], focusing on a file being updated
>> >>> - tried to illustrate examples of IVPTs in this example
>> >>> - highlighted an example of IVPT that I don't know how to handle.
>> >>>
>> >>> In this example, it would be good to see
>> >>> - where we have consensus
>> >>> - where we have disagreement
>> >>> - how we handle the outstanding example (i0) of IVPT
>> >>>
>> >>> Feedback by email or on wiki welcome!
>> >>>
>> >>> Cheers,
>> >>> Luc
>> >>>
>> >>>
>> >>> [1]
>> >>> http://lists.w3.org/Archives/Public/public-prov-wg/2011Jun/0096.html
>> >>> [2]
>> >>> http://lists.w3.org/Archives/Public/public-prov-wg/2011Jun/0069.html
>> >>> [3] http://www.w3.org/2011/prov/wiki/FileExample
>> >>>
>> >>> --
>> >>> 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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>> _____________________________________________________________
>> _______
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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
>> >
>> >
>> >
>> >
>> _____________________________________________________________
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>>
>>
>>
>> --
>> Dr Simon Miles
>> Lecturer, Department of Informatics
>> Kings College London, WC2R 2LS, UK
>> +44 (0)20 7848 1166
>
>
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-- 
Dr Simon Miles
Lecturer, Department of Informatics
Kings College London, WC2R 2LS, UK
+44 (0)20 7848 1166
Received on Friday, 17 June 2011 10:53:14 GMT

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