- From: Ryan Golden <ryan.golden@oracle.com>
- Date: Mon, 25 Jul 2011 13:35:16 -0500
- To: public-prov-wg@w3.org
- Message-ID: <4E2DB764.50806@oracle.com>
Clarification: when I said "except for Jim's," I was referring to Jim McCusker (not Jim Myers or other Jim's). --R On 7/25/2011 12:57 PM, Ryan Golden wrote: > I don't have a huge problem with "pil:snapshot," "pil:perspective," or > "pil:view" as opposed to "pil:entity." To me, most of the proposed > conceptualizations on the BOB topic at this point are isomorphic > (except for Jim's)--we're just debating on terminology. > > One thing I would point out, though. In a set of provenance > assertions, the terms "snapshot," "perspective," and "view" may subtly > imply an "IVP of" style relationship, which may not necessarily be the > case. If I assert "View B is derived from View A," the natural > language term "view" makes a subtle implication (to me at least) that > View B and View A are different views /of the same thing/. This is > not necessarily the case. For example, "view" would look a bit funny > in this assertion, whereas entity would not: "Oxygen is derived from > Air (by the process of distillation)." > > Nevertheless, I could be happy with any of these terms for now. > > --Ryan > > On 7/25/2011 11:39 AM, Paolo Missier wrote: >> Khalid just managed to put "snapshot", "perspective" and "view" in >> the same sentence. I see this as a good sign :-) >> >> So, having put in a good word earlier for a variation of "snapshot", >> I would like to go back for a moment to "view", as intended in the >> database sense. >> >> As we all know a view is indeed a perspective on the underlying >> database, and it has two key characteristics: >> - it projects out irrelevant attributes (out of a potentially >> unbounded number of them, as in our case) >> - if you materialize a view, this materialization remains valid only >> as long as none of the attributes that it contains (those that matter >> to the view) change their value in the underlying DB. When that >> happens, you need to recompute the view (= create a new materialized >> view, at least conceptually). >> >> Isn't that what BOBs do? >> >> In PIL the database itself is made of "things" (in Luc's latest >> terminology as of today) that we can only talk about and partially >> reveal by creating (mutiple) views, each valid within some temporal >> window, which is defined by value change events in its attributes. >> >> this also avoid the "frozen in time" connotation that snapshots have >> in several contexts. >> >> -Paolo >> >> On 7/25/11 11:07 AM, Khalid Belhajjame wrote: >>> On 25/07/2011 10:24, Luc Moreau wrote: >>>> The problem with Snapshot (like state, etc), is that it is the >>>> snapshot of an entity. >>>> We just don't want to distinguish an entity from its state, or an >>>> entity from its snapshot. >>> On the other hand, Snapshot has the advantage of conveying the fact >>> that >>> it is a description from a certain perspective (view). >>> >>> khalid >>> >>>> Hence, using Entity avoids this problem. >>>> >>>> Luc >>>> >>>> On 07/25/2011 10:19 AM, Paul Groth wrote: >>>>> I thought we were getting somewhere with snapshot..... >>>>> >>>>> I don't think ENTITY really captures the intuition behind a BOB. It's >>>>> too general. >>>>> >>>>> thanks, >>>>> Paul >>>>> >>>>> Luc Moreau wrote: >>>>>> 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 >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>> >> >>
Received on Monday, 25 July 2011 18:35:52 UTC