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Re: Tim's approach on Involvement

From: Timothy Lebo <lebot@rpi.edu>
Date: Tue, 21 Feb 2012 11:58:25 -0500
Cc: Daniel Garijo <dgarijo@delicias.dia.fi.upm.es>, Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>, "public-prov-wg@w3.org Group" <public-prov-wg@w3.org>
Message-Id: <D3D3FBD1-C4B0-4765-8D16-2232B3C09242@rpi.edu>
To: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>

On Feb 21, 2012, at 7:17 AM, Stian Soiland-Reyes wrote:

> 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.


On each of the Involvement classes, we could add a min 1 cardinality on the inverse of the subproperty of prov:involved.

I don't know how to do this cleanly without defining the inverses though.

It would be nice to add an axiom on Usage to say: "Activities use the prov:used property to point at instances of Usage."



> 
>> @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.
> 

involvedEntity ?

> 
> 
>> 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.



Do you see this as a show stopper? I don't think it is.

-tim



> 
> 
> -- 
> Stian Soiland-Reyes, myGrid team
> School of Computer Science
> The University of Manchester
> 
Received on Tuesday, 21 February 2012 17:09:01 GMT

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