# Re: definition of derivation?

From: Simon Miles <simon.miles@kcl.ac.uk>
Date: Tue, 21 Jun 2011 13:31:19 +0100
Message-ID: <BANLkTi=Va2dkODXt7oJBExXVeEcPx=Wgmg@mail.gmail.com>
To: Provenance Working Group WG <public-prov-wg@w3.org>
```Paul, Luc,

I'm OK with the definition, but I think it could be simplified and
clarified a little, and suggest:

Derivation represents how stuff is transformed from or affected by
other stuff. A thing B is derived from a thing A if the values of some
invariant properties of B are at least partially determined by the
values of some invariant properties of A.

The reasons for this proposed revision:

1. "A was used (and therefore created) before B was created" means the
definition of "derivation" is based on those for "use" and
"generation". This property seems, in practice, necessitated by B
having been determined by A anyway.

2. The first sentence mixes plural with singular, so it is unclear how
many things a derivation relates.

3. The "in the real world" caveat seems unnecessary if "things" are
defined to be explicitly about the real world. Moreover, if we decide
to revise the definition of "thing" to cover more than the real world,
then derivation would also have to be revised.

Thanks,
Simon

On 20 June 2011 21:07, Paul Groth <pgroth@gmail.com> wrote:
> Hi All,
>
> What do people think of Luc's definition of derivation:
>
> - http://www.w3.org/2011/prov
> /wiki/ConceptDerivation#Definition_by_Luc_.28in_terms_of_properties.29
> Things represent stuff in the real-world.
>
> Definition of Derivation. A derivation represents how stuffs are
> transformed or affect each other in the real world.
>
> A thing B is derived from a thing A if:
>
> A was used (and therefore created) before B was created
> The values of some invariant properties of B are partially determined by
> the values of some invariant properties of A
>
> James you seemed to suggest another way to define derivation or not
> define it all? Can you be more specific?
>
>
> Thanks,
> Paul
>
>
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--
Dr Simon Miles
Lecturer, Department of Informatics
Kings College London, WC2R 2LS, UK
+44 (0)20 7848 1166
```
Received on Tuesday, 21 June 2011 12:31:56 GMT

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