- From: Paul Groth <p.t.groth@vu.nl>
- Date: Tue, 17 Jan 2012 20:56:38 +0100
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- CC: Paolo Missier <Paolo.Missier@ncl.ac.uk>, Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Hi Luc, Stain, Paolo I'm not Paolo or Stain but I'll answer your question from my point of view...Yes, I think we say that from the perspective of the asserter entities characterize the same thing. I think Paolo is right on this. That indeed your saying from your prespective that entity(paolo) and entity(stain) refer to the same the same thing. From my perspective, as a cafe owner this might very well be indeed true...to me the customerOnRedChair might always be same thing, from my perspective what matters is the characteristics of being on the red chair and in my cafe. The fact that the whole changing of actual people happened may not be important from my perspective - indeed the characteristics of being paolo and stian could very well overlap and that might be what I want to talk about the provenance of. cheers, Paul Luc Moreau wrote: > Hi Paolo, Stian > > To answer the transitivity question, we need to answer a question. > Can an entity characterise different things? If yes, I agree > transitivity does not necessarily hold. If no, transitivity holds. > > Professor Luc Moreau Electronics and Computer Science University of > Southampton Southampton SO17 1BJ United Kingdom > > On 17 Jan 2012, at 16:37, "Paolo Missier"<Paolo.Missier@ncl.ac.uk> > wrote: > >> Hi Stian, >> >> but really, alternateOf() is designed /precisely/ to provide to >> say that e1, e2, are different characterizations of the /same >> thing/. >> >> So if you assert >> >> alternateOf(paoloInCafe, customerOnRedChair) >> >> then you are indeed saying that they are the same thing, only using >> different characterizations. And if you then also assert that >> >> alternateOf(stianInCafe, customerOnRedChair) >> >> then inferring that >> >> alternateOf(paoloInCafe, stianInCafe) >> >> is exactly what you want. If they are meant to be different things >> in the world, then one of the two assertions should not be there in >> the first place, right? >> >> I hope we can agree on this! >> >> --Paolo >> >> >> On 1/17/12 3:14 PM, Stian Soiland-Reyes wrote: >>> On Mon, Jan 16, 2012 at 14:31, Paolo >>> Missier<Paolo.Missier@ncl.ac.uk> wrote: >>> >>>> I think of alternateOf as non-functional and transitive, which >>>> gives us "clusters of alternates". We may later decide that it >>>> is convenient to add properties that make a set of alternates >>>> into a lattice. >>> No, not transitive. >>> >>> entity(customerOnRedChair, [prov:location="the red chair in the >>> cafe"]) entity(paoloInCafe) entity(stianInCafe) entity(paolo) >>> entity(stian) >>> >>> specializationOf(paoloInCafe, paolo) >>> specializationOf(stianInCafe, stian) >>> >>> alternateOf(paoloInCafe, customerOnRedChair) >>> alternateOf(stianInCafe, customerOnRedChair) >>> >>> >>> but we probably don't want to then infer: >>> alternateOf(paoloInCafe, stianInCafe) >>> >>> and certainly not: alternateOf(paolo, stian) >>> >>> .. neither did overlap the old characterisation intervals, and >>> are different 'things' in the world. >>> >>> >>> however, if Paolo and Stian did not sit anywhere else but in the >>> red chair, we can also have: >>> >>> >>> specializationOf(paoloInCafe, >>> customerOnRedChair)specializationOf(stianInCafe, >>> customerOnRedChair) this implies that for the duration of >>> paoloInCafe, it was also customerOnRedChair. >>> >> >> -- ----------- ~oo~ -------------- Paolo Missier - >> Paolo.Missier@newcastle.ac.uk, pmissier@acm.org School of Computing >> Science, Newcastle University, UK >> http://www.cs.ncl.ac.uk/people/Paolo.Missier >> >
Received on Tuesday, 17 January 2012 19:57:12 UTC