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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 17:08:16 +0100
Message-ID: <4E2C4370.1050000@cs.man.ac.uk>
To: "Myers, Jim" <MYERSJ4@rpi.edu>
CC: Paul Groth <p.t.groth@vu.nl>, Provenance Working Group WG <public-prov-wg@w3.org>, Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
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 16:08:47 UTC

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