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

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Tue, 8 May 2012 21:52:17 +0000
To: Timothy Lebo <lebot@rpi.edu>
CC: "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Message-ID: <EMEW3|140ebb695d537392eba8095f9dd3f7c3o47MqK08L.Moreau|ecs.soton.ac.uk|66A3CB76-9E6F-44F7-ABE4-A02C527BD559@ecs.soton.ac.uk>
Hi Tim,
Yes, it would remain EntityInvolvement, with optional hadActivity.
Luc

Professor Luc Moreau
Electronics and Computer Science
University of Southampton
Southampton SO17 1BJ
United Kingdom

On 8 May 2012, at 22:48, "Timothy Lebo" <lebot@rpi.edu<mailto:lebot@rpi.edu>> wrote:

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<mailto: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<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
Received on Tuesday, 8 May 2012 21:52:54 GMT

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