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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 17:08:20 +0100
Message-ID: <4FA944F4.2050801@ncl.ac.uk>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
CC: Daniel Garijo <dgarijo@delicias.dia.fi.upm.es>, 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>
that seems straightforward. it includes the case where 'e' is a signal, which may sometimes matter to mention explicitly


On 5/8/12 4:58 PM, Luc Moreau wrote:
> Hi all,
> Yes overloading was ruled out.
> Another option in the spirit of what Tim suggested is:
> wasStartedBy(a2,e,a1,t,attrs)
> With optional activity a1, entity e, time t.
> We would allow
> wasStartedBy(a2,e,-,t,attrs):The current form
> wasStartedBy(a2,-,a1,t,attrs): equivalent to wasstartedbyactivity
> wasStartedBy(a2,e,a1,t,attrs): the form where entity is explicit as requested by some
> Thoughts?
> Professor Luc Moreau
> Electronics and Computer Science
> University of Southampton
> Southampton SO17 1BJ
> United Kingdom
> On 8 May 2012, at 16:42, "Paolo Missier" <Paolo.Missier@ncl.ac.uk <mailto:Paolo.Missier@ncl.ac.uk>> wrote:
>> 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

-----------  ~oo~  --------------
Paolo Missier - Paolo.Missier@newcastle.ac.uk, pmissier@acm.org
School of Computing Science, Newcastle University,  UK
Received on Tuesday, 8 May 2012 16:08:50 GMT

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