- From: Timothy Lebo <lebot@rpi.edu>
- Date: Tue, 21 Feb 2012 11:58:25 -0500
- To: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
- 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>
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 UTC