- From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
- Date: Tue, 07 Jun 2011 19:32:06 +0100
- To: Paolo Missier <Paolo.Missier@ncl.ac.uk>
- CC: public-prov-wg@w3.org
Hi Paolo > > it's a good start, in that it subsumes observing value of data, and > therefore the state of a database, for example. > But we also need to observe /events/, don't we. For example, data that > moves along a communication channel that connects two processors. > Someone forwarding an online post. Or responding to the post. I was wondering if, instead, 'events' can be seen as a means for observing (or monitoring) changes, in particular changes in state. Would that be fair? khalid > > Also, in abstract, consider a state machine, "how did the machine > reach state S" is a legitimate provenance query (methinks). Then I > guess you may want to observe state transitions? > > I see two possible complications: > - not all transitions are observable (completeness of provenance) > - observers may be unreliable (correctness of provenance) > > --Paolo > > On 6/7/11 7:51 AM, Carl Reed wrote: >> For what its worth, the following definitions are from several ISO >> documents >> for Observations and Measurements - which relate directly to the >> semantics >> of observable properties, such as for sensors. >> >> observation >> >> act of observing a property >> >> NOTE The goal of an observation may be to measure or otherwise >> determine the value of a property >> >> property >> >> facet or attribute of an object referenced by a name >> >> [ISO 19143:2010, definition 4.21] >> >> EXAMPLE Abby's car has the colour red, >> where >> "colour red" is a property of the car instance >> >> And the one I enjoy: Observable - ability to be observed, possible to >> observe, and so forth. The use of "observable" in physics and quantum >> mechanics is very specific but essentially a sub-class of the general >> definition. >> >> Anyway, observables are properties such as "temperature", "height", >> "colour", "material". >> >> Cheers >> >> Carl >> >> ----- Original Message ----- >> From: "Paul Groth"<pgroth@gmail.com> >> To: "Luc Moreau"<L.Moreau@ecs.soton.ac.uk> >> Cc:<public-prov-wg@w3.org> >> Sent: Tuesday, June 07, 2011 1:11 AM >> Subject: Re: PROV-ISSUE-19: is this observable or not observable? >> >> >>> Hi All, >>> >>> Can someone attempt to provide a clean notion of what observable and >>> non-observable mean in this context. >>> >>> Thanks, >>> Paul >>> >>> On Tue, Jun 7, 2011 at 9:00 AM, Luc Moreau<L.Moreau@ecs.soton.ac.uk> >>> wrote: >>>> Dear all, >>>> >>>> When we discussed the notion of 'Invariant View or Perspective on a >>>> Thing, >>>> there were >>>> suggestions that it should be observable, and counter-suggestions >>>> that it >>>> should not be. >>>> >>>> It would be good to discuss both sides of the argument, in an >>>> attempt to >>>> reach consensus. >>>> >>>> Best regards, >>>> Luc >>>> >>>> >>>> >>>> >>> >> > >
Received on Tuesday, 7 June 2011 18:32:50 UTC