W3C home > Mailing lists > Public > public-prov-wg@w3.org > July 2011

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 19:43:42 +0100
Message-ID: <4E2C67DE.4020508@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, 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 18:44:10 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 13:06:37 GMT