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Re: [provo] Difference between wasInformedBy and wasStartedByActivity (ttl examples)

From: Paolo Missier <Paolo.Missier@ncl.ac.uk>
Date: Tue, 08 May 2012 16:41:50 +0100
Message-ID: <4FA93EBE.3070703@ncl.ac.uk>
To: Daniel Garijo <dgarijo@delicias.dia.fi.upm.es>
CC: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, Timothy Lebo <lebot@rpi.edu>, Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>, Jun Zhao <jun.zhao@zoo.ox.ac.uk>, W3C provenance WG <public-prov-wg@w3.org>
Hi,

that activities are not entities was decided a long time ago, I think  (I have no access to the archives at the moment). changing 
that would have unclear implications on the "provenance of activities".
I also seem to remember that wasStartedBy was indeed initially overloaded as suggested here, and that was found to be confusing.

-Paolo


On 5/8/12 3:02 PM, Daniel Garijo wrote:
> Hi Stian,
> instead of removing the constraint that entity and activity are disjoint we could
> also (as another possibility) have activities OR entities as possible domain
> of wasStartedBy. Now that we agreed on having an OWL-RL ++ profile,
> this would be possible.
>
> Thus, we would drop wasStartedByActivity, since wasStartedBy would
> cover already the desired functionality, right?
>
> Thanks,
> Daniel
>
> 2012/5/8 Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk <mailto:soiland-reyes@cs.manchester.ac.uk>>
>
>     On Mon, May 7, 2012 at 3:48 PM, Timothy Lebo <lebot@rpi.edu <mailto:lebot@rpi.edu>> wrote:
>
>     > +1, repositioning wasStartedByActivity as a "blurrier" form of wasStartedBy seems to finally find a place for it in the model.
>     > Though, like Khalid, I'm not sure it will be used much, or correctly.
>
>     It will certainly still be confusing, as it was for me. As you said,
>     most wasStartedBy() would also come with a twin used() relationship
>     (and therefore imply a wasInformedBy() relation).   At some point
>     wasStartedBy was sub-property of wasInformedBy (making the choice
>     simple) - but not anymore.
>
>     As Luc raised, why not also wasEndedByActivity,  wasStartedByAgent etc.?
>
>
>     So it might just not be worth it to keep wasStartedByActivity(). It's
>     a bad sign if it's confusing to even the ontology designers, then how
>     is any meaningful provenance exchange happen, where one party apply
>     wasInformedBy like wasStartedByActivity, and the other the opposite?
>
>
>
>     A second solution would be to remove the constraint that activity and
>     entity are disjoint. Then you could say wasStartedBy(a2, a1),
>     wasEndedBy(a2, a3) etc. - the activity can play the role of an entity
>     as well, rather than inventing invisible phantom token entities. We
>     are talking blurry provenance here, right, we don't know quite the
>     nature of the interaction.
>
>
>
>     > How can it be reframed so that wasStartedByActivity can "grow" in details like Derivation does with hadActivity, hadUsage,
>     and hadGeneration?
>
>     By adding a separate wasStartedBy() I would believe you have given all
>     the information (as an activity can only be started once).  Or is it
>     allowed to be wasStartedBy() two or more entities..? Luc?
>
>
>     --
>     Stian Soiland-Reyes, myGrid team
>     School of Computer Science
>     The University of Manchester
>
>


-- 
-----------  ~oo~  --------------
Paolo Missier - Paolo.Missier@newcastle.ac.uk, pmissier@acm.org
School of Computing Science, Newcastle University,  UK
http://www.cs.ncl.ac.uk/people/Paolo.Missier
Received on Tuesday, 8 May 2012 15:42:23 GMT

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