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

From: Paul Groth <p.t.groth@vu.nl>
Date: Sun, 24 Jul 2011 22:12:38 +0200
Message-ID: <81A678C2-E73F-4D99-99A9-CB1DAF8121A0@vu.nl>
CC: "Groth, P.T." <p.t.groth@vu.nl>, "Myers, Jim" <MYERSJ4@rpi.edu>, Provenance Working Group WG <public-prov-wg@w3.org>, Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
To: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
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)
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>> 
> 
Received on Sunday, 24 July 2011 20:13:14 GMT

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