W3C home > Mailing lists > Public > public-prov-wg@w3.org > July 2011

Re: PROV-ISSUE-30 (name-for-bob): What name do we use for the BOB construct? [Conceptual Model]

From: Ryan Golden <ryan.golden@oracle.com>
Date: Mon, 25 Jul 2011 13:35:16 -0500
Message-ID: <4E2DB764.50806@oracle.com>
To: public-prov-wg@w3.org
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 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 13:06:37 GMT