- From: Graham Klyne <GK@ninebynine.org>
- Date: Mon, 25 Jul 2011 18:44:05 +0100
- To: "Myers, Jim" <MYERSJ4@rpi.edu>
- CC: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, public-prov-wg@w3.org
Yes, yes, yes! And +1. Thank for for articulating this. I wholly agree. I think that a formal distinction between Entity and "Bob" is like a cracked pavement waiting to trip (or confuse) the unwary. #g -- Myers, Jim wrote: > +1. I think our challenge in PIL is to recognize that there are no > distinctions in the model we're discussing between very long-lived, > highly mutable Bobs and very short-lived, highly constrained ones. I can > talk about 'Jim was born', I can distinguish between childJim and > adultJim, or naiveJim and educatedJim to talk about learning, or > hungryJim and fullJim - all of these are valid things to record > provenance about. Other than the 'unchanging idea of Jim' (I've heard of > 'historical Lincoln' as being this type of unchanging view) which would, > by definition, have no provenance, PIL needs to be able to talk about > all the other types of Bobs. Some of those will look like snapshots, but > most don't. If Jim-with-a-license is the snapshot of me that was created > when I took my driver's test, it's one that lasts for tens of years.... > > I think we'll have much better luck explaining to the world if we start > by saying PIL provides a model to talk about the provenance of entities > which include all of the types of things you already give identifiers to > - people, documents, The Royal Society, etc. Then we point out that PIL > has made the modeling choice to treat change internal to an entity via > the definition of new entities that represent the original in specific > contexts - a document with a fixed content is modeled as a version of > that document, copies represent the same logical file in different > places, we define "They Royal Society in London during period X", or > "They Royal Society at its 300th meeting", if we want to describe its > evolution, etc. Again, it is clear because that is already done - > versions and copies and FRBR expressions/manifestations are already > understood to be entities in common sense terms. The fact that some of > these look like a bit like 'snapshots' and that our examples can > include very odd entities (Jim-when-he-breathed-out-just -now) is just > due to the granularity and the subject of the examples getting to a > finer scale than we discuss in casual conversation, not due to a > difference in kind. (Entities that represent me before and after > breathing might be useful if we're in a medical context, but it is the > complexity of that context that makes tracking the provenance of such > non-traditional entities useful... our unease with such ephemeral > entities is really due to our unfamiliarity with the intricacies of > medicine that make it useful to distinguish them). > > Assuming that there is only one type of Bob - if we start from the > terminology of snapshot, we'll have to explain how PIL is relevant to > people who want to describe the history of objects/things/entities. (I > have a file, it has an identifier, and to use PIL I have to create a new > identifier and think in terms of a snapshot of that file which is > somehow not the file, even in cases where I just want to talk about > unchanging content (my server generated a license file for customer X)). > > (If one really thinks we should have PIL:entities and PIL:snapshots both > in the model - versus just one concept that has to be renamed from Bob - > then we have more challenges to explain the difference in terms of what > they can be used for in the model as well as to provide guidance on when > to use which concept - both hard when the world already mixes them > (versions are objects and they are snapshots of documents - what are > they in PIL?) > > Jim > >> -----Original Message----- >> From: public-prov-wg-request@w3.org [mailto:public-prov-wg- >> request@w3.org] On Behalf Of Luc Moreau >> Sent: Monday, July 25, 2011 4:39 AM >> To: public-prov-wg@w3.org >> Subject: Re: PROV-ISSUE-30 (name-for-bob): What name do we use for the > BOB >> construct? [Conceptual Model] >> >> >> The word 'Entity' should also be considered for the construct BOB. >> >> If we do so, the text 'characterized entity' should be replaced by > something else >> in the draft specification. >> Why not 'thing'? >> >> >> So, the text could become: >> >> Section 4. >> In the world (whether real or not), there are things, which can be >> physical, digital, conceptual, or otherwise, and activities involving >> things. >> Words such as thing or activity should be understood with their >> informal meaning. >> This specification is concerned with characterized things, that is, >> things and their situation in the world, as perceived by the asserter. >> >> Section 5.1 >> An ENTITY represents an identifiable characterized thing. >> >> >> Luc >> >> On 07/24/2011 11:43 PM, Reza B'Far wrote: >>> First, for the record Khalid was the person suggesting Snapshot :) >>> >>> The way I've seen snapshot used commercially, it's fairly consistent >>> with the current definition of BOB. There is some murkiness on both >>> sides (how "snapshot" is used commercially and I think we're still >>> iterating here on the definition of BOB, but may be that's close to > be >>> finalized). However, I think they are close enough. What I liked >>> about "Snapshot" is that its intuitive and is used in several > domains >>> that I know of (content management, legal, configuration systems, > and >>> I've also seen use-cases in microfilm production by old-school >>> librarians). Also, I think "Snapshot" offers a huge advantage that >>> it's neither explicitly linked to the entity nor its state. And I >>> know the distinction between entity vs. entity's state and how > that's >>> articulated has been in a lot of the discussions. Using "Snapshot" >>> sort of obsoletes that discussion. >>> >>> On 7/24/11 12:57 PM, Stephan Zednik wrote: >>>> I am not partial to snapshot, partially because of the extensive >>>> functional usage of the term. I have always associated a snapshot >>>> with a point in time, not a duration - but this may be an incorrect >>>> association. >>>> >>>> I am open to discussing it, but my initial inclination was negative >>>> towards it. >>>> >>>> Will we use the same definition as we have been using for BOB? >>>> >>>> --Stephan >>>> >>>> On Jul 24, 2011, at 9:52 AM, "Reza B'Far"<reza.bfar@oracle.com> > wrote: >>>>> I second the term "Snapshot". This term also has functional usage >>>>> in several commercial application categories used within roughly > the >>>>> same meaning. >>>>> >>>>> On 7/24/11 3:45 AM, Khalid Belhajjame wrote: >>>>>> Hi Stephan, >>>>>> >>>>>> Given the example you gave in your previous email, I think that >>>>>> "EntitySpanshot" or "Snapshot" should be fine, given that it >>>>>> reflect the fact that it is a description of an entity that holds >>>>>> for some period of time. >>>>>> >>>>>> Do you agree? >>>>>> >>>>>> khalid >>>>>> >>>>>> On 23/07/2011 20:24, Stephan Zednik wrote: >>>>>>> I do not feel that EntityInstance, EntityInstantiation, or >>>>>>> InstantiatedEntity make sense for the book ownership scenario, > or >>>>>>> any scenario modeling the provenance of changes in > characteristics >>>>>>> of a physical object. >>>>>>> >>>>>>> To reiterate the example since I haven't committed it to a wiki >>>>>>> page yet. Book X is an entity that represents a real world >>>>>>> object. It can be put on a shelf, loaned to friends, damaged, >>>>>>> and/or destroyed. It has important characteristics (condition, >>>>>>> ownership, location, etc) that may change over the life of the >>>>>>> book. We may want to represent the provenance of the book as a >>>>>>> chain of ownership. >>>>>>> >>>>>>> |<----------------------------------------------------- Book X >>>>>>> > ----------------------------------------------------------------->| >>>>>>> |<!------ Book X with owner A ---->|<----Book X with owner B >>>>>>> ---->|<---- Book X with owner A --------->| >>>>>>> >>>>>>> If a book changes ownership, is the "book with changed > ownership" >>>>>>> a different EntityInstance? A different InstantiatedEntity? I >>>>>>> don't think what we current call a BOB is an 'instance of' >>>>>>> anything. I think of it as a description of an entity that > holds >>>>>>> for some time period (not necessarily given) for which >>>>>>> contextually important mutable characteristics of the the entity >>>>>>> are held to be known. >>>>>>> >>>>>>> --Stephan >>>>>>> >>>>>>> On 7/22/2011 5:29 AM, Curt Tilmes wrote: >>>>>>>> On 07/22/2011 03:43 AM, Khalid Belhajjame wrote: >>>>>>>>> The term "Snapshot" was suggested some time ago, and it seems > that >>>>>>>>> several people did like it. >>>>>>>>> We can also use the term "EntitySnapshot". >>>>>>>> Following from snapshot: >>>>>>>> >>>>>>>> EntityInstance >>>>>>>> EntityInstantiation >>>>>>>> InstantiatedEntity >>>>>>>> >>>>>>>> Curt >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >> -- >> Professor Luc Moreau >> Electronics and Computer Science tel: +44 23 8059 4487 >> University of Southampton fax: +44 23 8059 2865 >> Southampton SO17 1BJ email: l.moreau@ecs.soton.ac.uk >> United Kingdom http://www.ecs.soton.ac.uk/~lavm >> > > >
Received on Monday, 25 July 2011 17:45:27 UTC