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

From: Timothy Lebo <lebot@rpi.edu>
Date: Tue, 8 May 2012 17:48:44 -0400
Cc: public-prov-wg@w3.org
Message-Id: <0DA4F40E-A77F-48C8-97E0-8A2A874A66F2@rpi.edu>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Luc,

I like how either an Entity or Activity can be optional in a Start. It seems flexible for the variety of perspectives one may have or want to take.

Would Start always be a EntityInvolvement with an optional hadActivity?
I am comfortable with this, since regardless of whether you name/describe the entity, the trigger was involved.

+1 to the new draft. It seems to resolve my concerns.

Regards,
Tim



On May 8, 2012, at 5:24 PM, Luc Moreau wrote:

> Hi Stian, Paolo, all,
> 
> I have encoded the proposal 
> https://dvcs.w3.org/hg/prov/raw-file/31e2dc0de82d/model/working-copy/wd6-wasStartedBy.html
> 
> If people are happy, we can then adjust wasEndedBy similarly.
> I propose to take a vote on this on Thursday.
> 
> Luc
> 
> On 08/05/12 17:06, Stian Soiland-Reyes wrote:
>> 
>> That dual-mode style would confuse the interpretation of wasStartedBy, the activity becomes a token (and thus and entity)
>> 
>> Perhaps better would be to add the activity as an optional parameter to wasStartedBy in dm and add prov:hadActivity/prov:startedByActivity to prov:Start. It would mirror the activity of derivations.
>> 
>> An activity start, written wasStartedBy(id,a,e,t,a2, attrs) in PROV-N, has:
>> 
>> id: an OPTIONAL identifier for the activity start;
>> (..)
>> activity: an OPTIONAL activity (a2) which generated the (possibly unspecified) entity (e)
>> 
>> attributes: an OPTIONAL set (attrs)of attribute-value pairs representing additional information about this activity start.
>> 
>> Then mirror this for wasEndedBy.
>> 
>> -- 
>> Stian Soiland-Reyes, myGrid team
>> School of Computer Science
>> The University of Manchester
>> 
>> On May 8, 2012 3:03 PM, "Daniel Garijo" <dgarijo@delicias.dia.fi.upm.es> 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>
>> On Mon, May 7, 2012 at 3:48 PM, Timothy Lebo <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
>> 
>> 
Received on Tuesday, 8 May 2012 21:49:18 GMT

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