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

This would be true of USE as well - it will always be true that the bob
was used by the process execution after it occurs. Why is derivation
different?

(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.)

 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 14:35:51 UTC