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Re: PROV-ISSUE-67 (single-execution): Why is there a difference in what is represented by one vs multiple executions? [Conceptual Model]

From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
Date: Sat, 30 Jul 2011 09:04:14 +0100
Message-ID: <4E33BAFE.50905@cs.man.ac.uk>
To: Provenance Working Group WG <public-prov-wg@w3.org>
CC: Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>


I agree with you Simon. Probably, the only piece of information that one 
would get from differentiating between the two, is that:
1- isDerivedFrom(e1,e0): we don't know how many process executions have 
been enacted to generate e1 from e0.
2- isDerivedFromInMultipleSteps(e1,e0): we know that multiple process 
executions that were enacted to generate e1 from e0. (Although the text 
need to be changed to reflect this as explained below)

If the objective from differentiating between the two is as explained 
above, then I would suggest to change the text in Section 5.5.2 as follows:

"... this specification introduces a further assertion 
isDerivedFromInMultipleSteps(e1,e0), which may correspond to *one* or 
more process executions."

to

"... this specification introduces a further assertion 
isDerivedFromInMultipleSteps(e1,e0), which may correspond to *two* or 
more process executions."


Thanks, khalid


On 29/07/2011 17:52, Provenance Working Group Issue Tracker wrote:
> PROV-ISSUE-67 (single-execution): Why is there a difference in what is represented by one vs multiple executions? [Conceptual Model]
>
> http://www.w3.org/2011/prov/track/issues/67
>
> Raised by: Simon Miles
> On product: Conceptual Model
>
> By the definition, "a process execution represents an identifiable activity". This does not seem to preclude one process execution assertion denoting, at a coarse granularity, the same events in the world denoted by multiple process executions in other assertions.
>
> If so, then in the File Scenario example, I could add a coarse-grained process execution representing the whole e1-to-e5 activity:
>    processExecution(pe5,collaboratively-edit,t)
>    uses(pe5,e1,in)
>    isGeneratedBy(e5,pe5,out)
>
> But then Section 5.5.2 distinguishes between "a single process execution" and "one or more process executions". Following the argument above, these could represent exactly the same occurrences in the world.
>
> So there is no difference between what is denoted by one and multiple process executions, and so no difference between isDerivedFrom and isDerivedFromInMultipleSteps as described. Whether e5 was derived from e1 appears to me to be entirely independent of how many process executions were involved.
>
>
>
>
>
Received on Saturday, 30 July 2011 08:04:45 GMT

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