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

Hi Simon,

If I understand you correctly, you are suggesting that the following two 
assertions hold together.

isGeneratedBy(e5,pe5,out)
isGeneratedBy(e5,pe4,out)

But this is not legal, since it is stated that one BOB is generated by 
at most one process execution.

What you are suggesting should be encoded in a separate account (though 
we have not defined this yet!).
A one-step derivation then expands to one process execution in a given 
account.
In a separate account, there may be a multi-step derivation between the 
same two BOBs and it would
expand into multiple process executions.

Does it make sense?
Regards,

Luc


On 07/29/2011 05:52 PM, 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.
>
>
>
>
>    

-- 
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

Received on Monday, 1 August 2011 08:24:42 UTC