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Re: Tim's approach on Involvement

From: Daniel Garijo <dgarijo@delicias.dia.fi.upm.es>
Date: Tue, 21 Feb 2012 13:55:06 +0100
Message-ID: <CAExK0Ddzb3nCF4PbfYfi=t+WOYpcqkxzsh64_Z=hX8ZW_YYrgg@mail.gmail.com>
To: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Cc: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>, Timothy Lebo <lebot@rpi.edu>, "public-prov-wg@w3.org Group" <public-prov-wg@w3.org>
Thanks for the clarification, Stian.
A couple of things:

   1. what happened to Timed?
   2. I think we could have property "agent" subproperty of "entity" with
   domain "AgentInvolvement" and range "Agent".
   This will address some of the issues that Luc had yesterday about
   linking entities in associations.
   I realize that with the current restriction (entity only Agent) it may
   not be necessary, but I think it clarifies things for users.



2012/2/21 Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>

> On Tue, Feb 21, 2012 at 11:46, Daniel Garijo
> <dgarijo@delicias.dia.fi.upm.es> wrote:
> > Why the propery "tracedTo" is not a subproperty of "involved"? It
> relates an
> > Element to an Element too.
> Should be involved now.
> > Do we need "involved"? What is its use appart from creating a hierarchy?
> It shows that a binary relationship can also be expressed using
> qualified and Involvement. However the link from individual properties
> to that Involvement is not shown - it is by convention only.
> > @Stian: I don't see how Start could be an EntityInvolvement, could you
> > please explain? It is weird to have "End" under
> > activityInvolvement and not "Start" :)
> I know, I don't like it.
> This is due to prov:Start appearing in both
> http://www.w3.org/2011/prov/wiki/ProvRDF#Starting
> http://www.w3.org/2011/prov/wiki/ProvRDF#Starting_again
> however the second form does not talk about the agent. If I keep Start
> under AgentInvolvement, then the activity-to-activity Starting_again
> scenario would in OWL interpretation introduce a phantom agent.
> So now I left it at the top - but that would allow you to make a Start
> without either the agent and the activity. Perhaps this can be used
> for qualifying prov:startedAt.
> > I agree with Khalid in that "entity" and "activity" properties should be
> > renamed. From a usability pov is confusing to use
> > the same name for classes and properties (even if they are different
> URIs).
> Yes - we agreed in general earlier to use verb forms in past tense.
> The problem is to make the property name make sense for all the
> subclasses. "hadQualifiedEntity" obviously did not work well.
> > Are we going to delete the subproperties of "qualified"?
> Yes, that was an important aspect of Tim's approach.
> > Since qualified links an element to an Involvement, I think that we could
> > use them wrong:
> > :ent a prov:Entity;
> >       prov:qualified [ a prov:Usage;
> >                             prov:hadRole :role1]
> > This is consistent according to our ontology (usage has some entities,
> but
> > in the open world assumption it doesn't have to be asserted). Should we
> > allow it?
> There are lots of stupid things which are allowed by the OWL, for
> instance making multiple inconsistent Generations, having
> wasGeneratedAt times that don't overlap the startedAt/endedAt times of
> the generating activity, etc. Checking those kind of things should not
> be the job of the OWL ontology, but by a set a of rules.
> However the ontology should guide the user towards the correct usage.
> That's Tim's approach with the "hadSpatialExtent min 0 Location" kind
> of subclasses - that gives a hint that it could have a location,
> without requiring it.
> However super-properties and super-classes make it look like you can
> use them directly. It now looks like you can say:
> :entity1 prov:qualified [
>  a prov:EntityInvolvement;
>  prov:entity :entity2;
>  prov:hadTemporalExtent :t .
> ] .
> - but this is a half-baked statement where you don't know if we're
> talking about derivation, attribution or quotation. All  you can
> conclude is :entity1 prov:involved :entity2.  Perhaps that's a useful
> statement in a few applications, but for most parts it would be silly.
> --
> Stian Soiland-Reyes, myGrid team
> School of Computer Science
> The University of Manchester
Received on Tuesday, 21 February 2012 12:55:40 UTC

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