# Re: PROV-ISSUE-249 (two-derivations): Why do we have 3 derivations? [prov-dm]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Thu, 08 Mar 2012 22:02:24 +0000
Message-ID: <EMEW3|c7e899acb5ce661e68f69c8bb2cf7532o27M2W08L.Moreau|ecs.soton.ac.uk|4F592C70.6080506@ecs.soton.ac.uk>

```Hi all,

I propose to close this issue, since we have agreed today that the three
forms
of derivation should be replaced by a single one.
Any other concern about derivations should be raised against the document.

Cheers,
Luc

On 09/02/12 23:11, Provenance Working Group Issue Tracker wrote:
> PROV-ISSUE-249 (two-derivations): Why do we have 3 derivations? [prov-dm]
>
> http://www.w3.org/2011/prov/track/issues/249
>
> Raised by: Luc Moreau
> On product: prov-dm
>
> We currently have 3 derivations:
>
>
> A precise-1 derivation, written wasDerivedFrom(id, e2, e1, a, g2, u1, attrs)
> An imprecise-1 derivation, written wasDerivedFrom(id, e2,e1, t, attrs)
> An imprecise-n derivation, written wasDerivedFrom(id, e2, e1, t, attrs)
>
>
> Imprecise-1/imprecise-1 are distinguished with the attribute prov:steps.
>
> Why do we need 3 derivations?
>
> I believe that imprecise-n derivation is required for the 'scruffy provenance' use case.
>
> I believe that precise-1 derivation is required for the 'proper provenance' use case: in particular, it's a requirement for provenance based reproducibility.
>
> I don't understand why we have imprecise-1.  Why can we just have
> imprecise-n and precise-1?
>
> PS. If we go with this proposal, then they could simply be called imprecise/precise, and we don't need the attribute steps.
>
> PS2. They would essentially be a unqualified and a qualified derivation (in prov-o terminology).
>
>
>
>
>
>
```
Received on Thursday, 8 March 2012 22:02:57 GMT

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