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

From: Graham Klyne <GK@ninebynine.org>
Date: Mon, 25 Jul 2011 18:44:05 +0100
Message-ID: <4E2DAB65.5040108@ninebynine.org>
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.


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
>> 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 GMT

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