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Re: PROV-ISSUE-43 (derivation-time): Deriviation should have associated time [Conceptual Model]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Mon, 25 Jul 2011 09:21:50 +0100
Message-ID: <EMEW3|0b7244f6b565769dfc3c81076d91efe9n6O9Lr08L.Moreau|ecs.soton.ac.uk|4E2D279E.90904@ecs.soton.ac.uk>
To: public-prov-wg@w3.org


I'd like to refer to the missing inference I mentioned in a separate thread:

I think there is a missing "inference" in the specification.

If there isDerivedFrom(e1,e0) holds, then there exists a process 
execution pe, and roles r0,r1,
such that:
   isGeneratedBy(e1,pe,r1) and use(pe,e0,r0)


So, given isDerivedFrom(e1,e0), I would argue that there are potentially 
four
notions of time associated with this derivation:
- beginning of pe
- end of pe
- use of e0
- generation of e1

Paul, in your proposal, were you referring to any of these 4 instants, or
did you have another notion of time not captured yet?


Luc


On 07/24/2011 09:12 PM, Paul Groth wrote:
> Something like that...I need to look at the exact definition of derived from.
>
> Paul
>
> On Jul 24, 2011, at 20:43, Khalid Belhajjame<Khalid.Belhajjame@cs.man.ac.uk>  wrote:
>
>    
>>
>> Ok, I must admit I didn't understand that. Just to clarify, when one say
>> isDerivedFrom(b1,b2,t), does that means that b2 was created at t?
>>
>> Thanks, khalid
>>
>>
>> On 24/07/2011 18:33, Paul Groth wrote:
>>      
>>> Hi Khalid,
>>>
>>> I don't think this is what I mean.
>>>
>>> It's not when the assertion was made. It's when the derivation occurred according to the asserter.
>>>
>>> Just as with use and generation. It's the time at which these events occur according to the asserter.
>>>
>>> Thanks
>>> Paul
>>>
>>> On Jul 24, 2011, at 18:08, Khalid Belhajjame<Khalid.Belhajjame@cs.man.ac.uk>   wrote:
>>>
>>>        
>>>> On 24/07/2011 15:35, Myers, Jim wrote:
>>>>          
>>>>> (The time is not the interval over which the derivation relation is
>>>>> valid - in the same way the time on USED is not the time when that
>>>>> relation is valid (it would be if the semantics were 'in use during
>>>>> interval t') - both just describe the time when an enduring relationship
>>>>> was first formed.)
>>>>>            
>>>> Agreed, that what I was hinting to in my last response email to Paul.
>>>> The time I was referring to in my email was the validity, but Paul, I
>>>> think, was talking about the time where the derivation was formed.
>>>>
>>>> Which leads me to a new proposal. Instead of having the time as argument
>>>> to USE, GENERATION and derivation, e.g., isDerivedFrom(b1,b2,t). Would
>>>> it be sensible to assume, instead, that every assertion may be
>>>> associated with a time in which it was formed?
>>>>
>>>> Thanks, Khalid
>>>>
>>>>          
>>>>>   Jim
>>>>>
>>>>>            
>>>>>> -----Original Message-----
>>>>>> From: public-prov-wg-request@w3.org [mailto:public-prov-wg-
>>>>>> request@w3.org] On Behalf Of Khalid Belhajjame
>>>>>> Sent: Sunday, July 24, 2011 8:27 AM
>>>>>> To: Paul Groth
>>>>>> Cc: Provenance Working Group WG; Provenance Working Group Issue
>>>>>>              
>>>>> Tracker
>>>>>            
>>>>>> Subject: Re: PROV-ISSUE-43 (derivation-time): Deriviation should have
>>>>>> associated time [Conceptual Model]
>>>>>>
>>>>>>
>>>>>> Hi Paul,
>>>>>>
>>>>>> On 24/07/2011 13:13, Paul Groth wrote:
>>>>>>              
>>>>>>> Hi Khalid
>>>>>>> But why can't I say that a newspaper article is derived from a
>>>>>>>                
>>>>> picture at a
>>>>>            
>>>>>> particular time? Or for that matter over a period of time.
>>>>>>
>>>>>> The way I see it, is that there will be a bob representing the
>>>>>>              
>>>>> newspaper article
>>>>>            
>>>>>> and another representing the picture. If there is evidence that the
>>>>>>              
>>>>> latter is
>>>>>            
>>>>>> derived from the former, then the derivation will always hold between
>>>>>>              
>>>>> those
>>>>>            
>>>>>> two bobs.
>>>>>>
>>>>>> Now, that I am writing this email, I am wondering whether we are
>>>>>>              
>>>>> referring to
>>>>>            
>>>>>> the same notion of time. In your statement, isDerivedFrom(b1,b2,t), I
>>>>>>              
>>>>> think you
>>>>>            
>>>>>> mean t is used to refers to the time in which the derivation assertion
>>>>>>              
>>>>> was
>>>>>            
>>>>>> made, whereas what I was thinking of is the (period of) time in which
>>>>>>              
>>>>> the
>>>>>            
>>>>>> derivation holds. Is that the case?
>>>>>>
>>>>>> Thanks, khalid
>>>>>>              
>>>>>>> The time is when the derivation occurred not when it applies.
>>>>>>>
>>>>>>> Thanks
>>>>>>> Paul
>>>>>>>
>>>>>>> On Jul 24, 2011, at 13:06, Khalid
>>>>>>>                
>>>>>> Belhajjame<Khalid.Belhajjame@cs.man.ac.uk>     wrote:
>>>>>>              
>>>>>>>> Hi Paul,
>>>>>>>>
>>>>>>>> I think that "Use" and "Generation" should be associated with time.
>>>>>>>> However, I don't think we should associate time to derivation.
>>>>>>>> I would argue that isDerivedFrom(b1,b2) holds all time. Although b1
>>>>>>>> and
>>>>>>>> b2 may no longer exist, isDerivedFrom(b1,b2) is still valid.
>>>>>>>>
>>>>>>>> Thanks, khalid
>>>>>>>>
>>>>>>>>
>>>>>>>> On 23/07/2011 16:46, Provenance Working Group Issue Tracker wrote:
>>>>>>>>                  
>>>>>>>>> PROV-ISSUE-43 (derivation-time): Deriviation should have
>>>>>>>>>                    
>>>>> associated
>>>>>            
>>>>>>>>> time [Conceptual Model]
>>>>>>>>>
>>>>>>>>> http://www.w3.org/2011/prov/track/issues/43
>>>>>>>>>
>>>>>>>>> Raised by: Paul Groth
>>>>>>>>> On product: Conceptual Model
>>>>>>>>>
>>>>>>>>> Other relationships have time associated with them (e.g. use,
>>>>>>>>> generation, control)
>>>>>>>>>
>>>>>>>>> There is no optional time associated with derivation.
>>>>>>>>>
>>>>>>>>> Suggested resolution is to add the following to the definition of
>>>>>>>>>                    
>>>>>> isDerivedFrom:
>>>>>>              
>>>>>>>>> -  May contain a "derived from time" t, the time or time intervals
>>>>>>>>> when b1 was derived from b2
>>>>>>>>>
>>>>>>>>> Example:
>>>>>>>>> isDerivedFrom(b1,b2, t)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>                    
>>>>>            
>>      
>    

-- 
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, 25 July 2011 08:22:20 GMT

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