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Re: PROV-ISSUE-2: proposal to vote on - process execution in the past

From: James Cheney <jcheney@inf.ed.ac.uk>
Date: Tue, 14 Jun 2011 12:49:41 +0100
Cc: Provenance Working Group WG <public-prov-wg@w3.org>
Message-Id: <C74BFE29-C1E1-48FB-9AF1-875FBC3F9E74@inf.ed.ac.uk>
To: Simon Miles <simon.miles@kcl.ac.uk>
I'm neutral about either the original or Simon's alternative.  What do  
we gain by requiring that provenance records describe "the past" and  
not hypothetical scenarios?  This seems to open a pretty big can of  
worms - what about clock skew?  do we want to require that the records  
are "true" or "accurate" other senses too? etc.

As stated, this seems to suggest that whether or not a provenance  
record syntactically well-formed is time-dependent, which seems like  
an unnecessary obligation.  Simon's version also seems to require that  
we assign times to assertions (seems reasonable), and these might  
themselves have provenance (involving processes), etc.

Perhaps it is time to start breaking out MUST and SHOULD?  I would  
agree with "descriptions of process start times MUST precede their end  
times (if both are known) and SHOULD be in the past".

i.e., saying a process started today and ended yesterday is just  
nonsense, but describing a hypothetical process that starts tomorrow  
and ends Thursday is a little strange, but might be fine if we just  

I'd also be happy with "the start time of a process execution SHOULD  
precede the time the assertion is made", but not "MUST".

But maybe I'm being overly pedantic.


On Jun 14, 2011, at 12:29 PM, Simon Miles wrote:

> +1 except for the caveat made in the last teleconference, e.g. I might
> be modelling what I expect the provenance of something to be in 10
> years time, in which case the execution is in the past of an imagined
> future, not in the past from now.
> So I would qualify the definition to something like:
>  "the start of a process execution is always in the past, from the
> position of any assertion made about it."
> Thanks,
> Simon
> On 14 June 2011 11:48, Paul Groth <pgroth@gmail.com> wrote:
>> Hi All:
>> In trying to move towards a definition of process execution, it  
>> would be
>> good to get the groups consensus on the notion of process execution
>> being in the past. Namely, the following is proposed from the last  
>> telecon:
>> "A process execution has either completed (occurred in the past) or  
>> is
>> occurring in present (partially complete). In other words, the  
>> start of
>> a process execution is always in the past."
>> Can you express by +1/-1/0 your support for this proposal via a  
>> response
>> to this email message?
>> The due date for responses is this Thursday before the telecon.
>> Thanks,
>> Paul
>> ______________________________________________________________________
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> -- 
> Dr Simon Miles
> Lecturer, Department of Informatics
> Kings College London, WC2R 2LS, UK
> +44 (0)20 7848 1166

The University of Edinburgh is a charitable body, registered in
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Received on Tuesday, 14 June 2011 11:50:31 UTC

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