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

From: Paul Groth <p.t.groth@vu.nl>
Date: Tue, 26 Jul 2011 08:00:00 +0200
Message-ID: <8F167231-6E3F-4C6A-9A7D-00E1B4B84DC4@vu.nl>
CC: "Groth, P.T." <p.t.groth@vu.nl>, Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>, "Myers, Jim" <MYERSJ4@rpi.edu>, Provenance Working Group WG <public-prov-wg@w3.org>, Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
To: Satya Sahoo <satya.sahoo@case.edu>
```Hi Satya,

The definition of time we use (ISO??) allows for the expression of time intervals.

Paul

On Jul 26, 2011, at 3:14, Satya Sahoo <satya.sahoo@case.edu> wrote:

> Hi Paul and Khalid,
> > DerivedFrom(b1,b2,t), does that means that b2 was created at t?
> How do we represent a time duration (t1 to t2) instead of a time instant (t) - I am assuming that "t" above refers to a time instant, given that b2 can be derived from b1 over a period of time?
>
> Best,
> Satya
>
>
> On Sun, Jul 24, 2011 at 4:12 PM, Paul Groth <p.t.groth@vu.nl> 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 Tuesday, 26 July 2011 06:00:47 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 16:50:58 UTC