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Re: PROV-ISSUE-150: question on formal semantics of role in wasGeneratedBy relation [Formal Semantics]

From: Simon Miles <simon.miles@kcl.ac.uk>
Date: Wed, 21 Dec 2011 11:13:22 +0000
Message-ID: <CAKc1nHcW3uK6H8Wa1t79z9-EWAOvaBQMBQi9brSYjz5msYBPGA@mail.gmail.com>
To: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Stephan, Tim,
It seems this discussion has different aspects relating to PROV-O,
PROV-DM and the primer.

Could one of you raise the proposed changes to the primer with
rationale as a separate issue specifically for that document? The
"outputAggregatedDataset" naming suggestion makes sense to me and
seems a good idea, but I'm not clear on the rationale behind the
typing suggestion, so would be good if you can spell it out.

Thanks,
Simon
On 21 December 2011 10:42, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:
> Hi Stephan and Tim,
>
> Have we converged on this issue? Is there something that needs to be
> addressed in the
> prov-dm document?
>
> If yes, can you clarify? If not, then I propose we close the issue.
>
> Regards,
> Luc
>
>
> On 11/22/2011 04:25 PM, Timothy Lebo wrote:
>
>
> On Nov 14, 2011, at 5:23 PM, Provenance Working Group Issue Tracker wrote:
>
>
> PROV-ISSUE-150: question on formal semantics of role in wasGeneratedBy
> relation [Formal Semantics]
>
> http://www.w3.org/2011/prov/track/issues/150
>
> Raised by: Stephan Zednik
> On product: Formal Semantics
>
> I am slightly confused about the formal semantics of the role qualifier in a
> wasGeneratedBy relation.
>
> from http://www.w3.org/TR/prov-dm/#prov-dm-overview
>
> "Qualifiers can be associated to relations, namely use and wasGeneratedBy,
> in order to further characterize their nature. Role is a pre-defined
> qualifier."
>
> and from http://www.w3.org/TR/prov-dm/#expression-qualifier
>
> "The PROV data model introduces the qualifier role in the PROV-DM namespace
> to denote the function of a characterized thing with respect to an activity,
> in the context of a use/generation/control relation. The value associated
> with a role attribute must be conformant with Literal."
>
> I have sensed confusion in the prov-o discussions as to whether the role in
> a generation is played by the process execution or the generated entity.
>
>
>
> I don't think many people have misinterpreted the prov:hadRole's value to be
> the role of an Activity; it is the role of the Entity, as you cite from the
> DM above.
>
>
>  Can a generated entity play a role in the activity that generates it?
>
>
> Absolutely
>
>  Can a process execution play a role, that is be the characterized thing
> that has a function in an activity?
>
>
>
> The Activity is self-roling. It's existence establishes its characterization
> and can be modeled explicitly by specializing Activity.
>
>
>  Does the definition of role need to be changed?
>
>
> I don't think so.
>
>
> I know discussion of role has taken up a lot of time, this sure has turned
> out to be a tricky issue, but I think getting qualifiers right is worth it.
>
> There is an example in the primer,
> http://dvcs.w3.org/hg/prov/raw-file/default/primer/Primer.html#roles-1,
>
>
>
> 1) The name  ex1:aggregated seems a bit odd, since it sounds like it is the
> output and not the activity itself.
>
> 2) I'd suggest adding types for Activities in the examples.
>
> but I am not sure if it is representative of the intent for role on a
> generation relation.
>
> ex1:aggregated
>   prov:hadQualifiedGeneration [ a prov:Generation ;
>       prov:hadQualifiedEntity ex1:aggregate1 ;
>       prov:hadRole ex1:aggregatedData
>   ] .
>
>
>
> Perhaps the example
> from http://www.w3.org/2011/prov/wiki/Qualifed_Involvements_in_PROV-O#Qualified_Generation_with_Roles
> would make roles of generated entities more clear:
>
> :pe
>     a prov:ProcessExecution;
>
>     prov:generated :output;
>     prov:hadQualifiedGeneration [
>        a prov:Generation;
>        prov:hadQualifiedEntity         :output;
>        prov:hadRole            workflow:output;
>     ];
>
>     prov:generated :metadata;
>     prov:hadQualifiedGeneration [
>        a prov:Generation;
>        prov:hadQualifiedEntity         :metadata;
>        prov:hadRole            workflow:metadata-of-output-with-log;
>     ];
> .
>
>
>
>
> -Tim
>
>
>
>
>
> --Stephan
>
>
>
>
>
>
> --
> Professor Luc Moreau
> Electronics and Computer Science   tel:   +44 23 8059 4487
> University of Southampton          fax:   +44 23 8059 2865
> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
> United Kingdom                     http://www.ecs.soton.ac.uk/~lavm



-- 
Dr Simon Miles
Lecturer, Department of Informatics
Kings College London, WC2R 2LS, UK
+44 (0)20 7848 1166

Provenance: The Bridge Between Experiments and Data:
http://eprints.dcs.kcl.ac.uk/1372/
Received on Wednesday, 21 December 2011 11:13:59 UTC

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