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Re: PROV-ISSUE-101 (Conceptual Model): Section 5.2.2 ProcessExecution (conceptual model document review) [Conceptual Model]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Tue, 08 Nov 2011 17:05:52 +0000
Message-ID: <EMEW3|02a40936631e410e2249bcb2b2c5478cnA7H5v08L.Moreau|ecs.soton.ac.uk|4EB96170.4040708@ecs.soton.ac.uk>
To: Timothy Lebo <lebot@rpi.edu>
CC: public-prov-wg@w3.org
Hi Tim,

I am about to make some edits to the event section.

On 11/08/2011 04:28 PM, Timothy Lebo wrote:
> I am troubled by the presence of these underlying "events" in the DM.
>
> Why are they not simply "time instants"?
>    
event is a common term in process algebra.  To me it's very important to 
be able to talk
about changes in the system (use of entity/generation/start of 
process/end of process) without
having to refer to time.
> I think it would be fair to consider a ProcessExecution an Event, in which case a proper interval Event is delimited by two time instant Events -- THREE events to describe one?
>
> It seems that "events" in DM exist only to delimit ProcessExecutions and the characterization intervals with singular moments in time.
>    

that's correct.
> If we keep "events" - could there be a description somewhere about why they are called that?
> I might see an argument that, if a characterization interval ends, SOMETHING would needed to have happened to end it.
>    

They allow us to provide a temporal interpretation of prov-dm.

I am not against changing the term. I personally find event well aligned 
with process algebra.

Luc

> Thanks,
> Tim
>
>
>
> On Nov 7, 2011, at 6:15 AM, Luc Moreau wrote:
>
>    
>> Hi Satya,
>>
>> With all the proposals that have been approved recently, it's now time to
>> answer some of the issues you raised. Find answers interleaved.
>>
>> I am proposing that this issue can now be closed.
>>
>> Best regards,
>> Luc
>>
>>      
>>> 1. The activity that a process execution expression is a
>>> representation of has a duration, delimited by its start and its end
>>> events; hence, it occurs over an interval delimited by two
>>> events. However, a process execution expression need not mention time
>>> information, nor duration, because they may not be known.
>>>
>>> Issue: Is it possible that event information, similar to time
>>> information, may not be known? Is it possible to define a PE without
>>> having knowledge about its start and end events and also its duration
>>> (delimited by events)?
>>>        
>> Yes, in fact, we don't assert the start/end events.
>>      
>    

-- 
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 Tuesday, 8 November 2011 17:06:40 UTC

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