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Re: generation by two distinct activities?

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Fri, 18 May 2012 14:40:46 +0100
Message-ID: <EMEW3|1b309e1a3df6638fe0e7b85ff0d03fdeo4HEen08L.Moreau|ecs.soton.ac.uk|4FB6515E.2060205@ecs.soton.ac.uk>
To: Timothy Lebo <lebot@rpi.edu>
CC: public-prov-wg@w3.org
Hi Tim,


Let me try and explain why I thought the constraint wouldn't be satisfied.

wasGeneratedBy(g1; ex:bottle, ex:manufacturing)
wasGeneratedBy(g2; ex:bottle, ex:purchasing)

I am assuming we can establish the following
(purchasing follows delivery which follows manufacturing)

g1 precedes g2

By definition:
wasGeneratedBy(g2; ex:bottle, ex:purchasing)
implies that ex:bottle didn't exist before g2.

By definition:
wasGeneratedBy(g1; ex:bottle; ex:manufacturing)
implies bottle existed after g1.

In the interval g1,g2, bottle seems to exist and not exist.

What we really want to say is:
wasGeneratedBy(g1; ex:bottle, ex:manufacturing)
wasGeneratedBy(g2; ex:bottle2, ex:purchasing)
alternateOf(ex:bottle2,ex:bottle)
The one you bought is the bottle that was on the shelve.
We can probably say that:
wasDerivedFrom(ex:bottle2,ex:bottle, [prov:type="transportation"])


So, in summary, it is fine to write
wasGeneratedBy(ex:bottle, ex:manufacturing)
wasGeneratedBy(ex:bottle, ex:purchasing)
It simply won't check the constraints.  It is in that sense that I think
it is not "proper" provenance.


Luc


On 05/17/2012 05:51 PM, Timothy Lebo wrote:
> On May 17, 2012, at 10:14 AM, Luc Moreau wrote:
>
>    
>> Hi Tim,
>>
>> This is "scruffy" provenance, and as such, should be accepted.
>>      
> How is it scruffy?
>
> The entity (the fixed attributes) hasn't changed, only some assertions about its provenance has.
>
>    
>> It wouldn't satisfy constraints though: so, it's not valid.
>>      
> So the distinct purchase activity imposed new fixed attributes of my water bottle (owner:Tim), without my permission?
> The entity that I'm talking about is only it's physical form (independent of squeezes).
>
> -Tim
>
>
>    
>> Luc
>>
>> On 05/17/2012 03:07 PM, Timothy Lebo wrote:
>>      
>>> prov-wg,
>>>
>>> I know this has been discussed before, but I'm still a bit confused.
>>>
>>> Can a single entity be generated by two distinct activities?
>>>
>>> I think in a distributed world of multiple perspectives, different asserters would look at the same entity and "carve up" activities differently that may not be necessarily the same.
>>>
>>> I'm sitting next to a water bottle.
>>> That same water bottle was generated by some activity in a factory, but it was also generated by my activity of driving to Target and handing over a Visa card.
>>> (and I don't care about reducing my bottle into "before I bought" and "after I bought" - I just want one bottle).
>>>
>>> Thanks!
>>> Tim
>>>
>>>
>>>
>>>        
>> -- 
>> 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
>>
>>
>>
>>      
>    

-- 
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 Friday, 18 May 2012 13:41:27 GMT

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