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

From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
Date: Sun, 24 Jul 2011 23:48:24 +0100
Message-ID: <4E2CA138.90705@cs.man.ac.uk>
To: Paul Groth <p.t.groth@vu.nl>
CC: "Myers, Jim" <MYERSJ4@rpi.edu>, Provenance Working Group WG <public-prov-wg@w3.org>, Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>

Ok thanks, I think I get it now.
khalid

On 24/07/2011 21:12, 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)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
Received on Sunday, 24 July 2011 22:49:19 GMT

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