Re: smaller example

Hi Jim,
I wanted to clarify the following point:
> * there is/are mutable property(ies) of A that is/are correspond to
immutable property(ies) of B (i.e. ones that are integral to B's
identity)

If a set of property(s) are integral to B's identity (and immutable), while
they are mutable for A - are these property(s) integral to A's identity
also?
Case I: If they are integral to A's identity I am not sure how can they be
mutable, else

Case II: If they are not integral then how can A and B represent the same
entity/part of the world (at any specific point in time) since the set of
identifying property(s) of two identical entities will also be identical?

> * If B is an IVP of A, they must have the same values for all immutable
properties they have in common (for their entire existences...).
Agree (identifying property(s) of an entity cannot change without changing
the identity of the entity)

>* The distinction between A and B becomes relevant when one is
discussing processes that affect the aspects of entity state represented
by the subset of properties that represent the shift of some aspect of
state from mutable in A to immutable in B.
This point does not follow from the previous point. Can we say that A and B
share mutable property(s) that have different values hence accounting for
the different perspectives/views?

This is a general point: I have tried to follow the discussion threads, both
the original thread on IVPT and the subsequent thread on Luc's smaller
example, but unfortunately I am still not sure how the IVPT concept is
applicable to the current data journalism example.

Thanks.

Best,
Satya


On Mon, Jun 13, 2011 at 2:30 PM, Myers, Jim <MYERSJ4@rpi.edu> wrote:

> FYI - Luc and I had a Skype call this morning to discuss a path forward
> on how to address invariance and we have tried to combine aspects of
> both alternatives from the working group discussion in a way that
> hopefully works and can gain consensus. A few more details below, but
> the general path is to model with one type of thing (ala IVP of T) but
> to push the definition of that type of thing to be independent of
> processes (ala IVPT). The question for the group is then whether this
> makes sense/looks like it helps/is consistent with other views/should be
> elucidated further, etc.
>
> Cheers,
>   Jim
>
>
> The following is my embellishment of what Luc and I discussed -
> hopefully still consistent with our discussion :-) I expect some further
> refinement will be needed to nail everything down.
>
> Definition of 'thing': In PIL, entities in the real world (described in
> terms of physical, digital, logical, conceptual, other vocabularies) are
> modeled as "things" that:
> * have an identity
> * model aspects of the entity's state as a set of properties of the
> "thing" that are invariant and considered integral to identity
> * model other aspects of the entity's state as a second set of
> properties that are mutable and able to change during the "thing"'s
> lifecycle, and therefore not integral to identity
>
> There are no assumptions that the sets of properties are complete as
> documented, or that the properties are independent/orthogonal of each
> other.
>
> Definition of "invariant view/perspective" (IVP):
>
> For A and B, both of which are "things", B is an  IVP of A iff
> * A and B represent the same entity/part of the real world at some
> instant in time (the set of properties they share must have identical
> values at that instant), and
> * there is/are mutable property(ies) of A that is/are correspond to
> immutable property(ies) of B (i.e. ones that are integral to B's
> identity)
>
> These definitions then have a number of implications:
> * If B is an IVP of A, they must have the same values for all immutable
> properties they have in common (for their entire existences...).
> * The distinction between A and B becomes relevant when one is
> discussing processes that affect the aspects of entity state represented
> by the subset of properties that represent the shift of some aspect of
> state from mutable in A to immutable in B. If B is an IVP of A at time
> t, B is an IVP of A is true for the whole interval between processes of
> this type.
>
> Etc.
>
>
> > -----Original Message-----
> > From: public-prov-wg-request@w3.org [mailto:public-prov-wg-
> > request@w3.org] On Behalf Of Luc Moreau
> > Sent: Monday, June 13, 2011 5:35 AM
> > To: Provenance Working Group WG
> > Subject: smaller example
> >
> > Dear all,
> >
> > PROV-ISSUE-1
> > PROV-ISSUE-8
> > PROV-ISSUE-19
> >
> > On June 7th [1], we agreed on "In a first instance, to define the
> necessary
> > concepts that allow us  to express the provenance of an invariant view
> or
> > perspective on a thing".
> > Putting this in practice turns out to be difficult.
> >
> > While the egg example is interesting, the scenario seems to evolve all
> the
> > time. Also, I thought that, in a first instance, we may want to look
> at things
> > that are digital, before seeing how our ideas extend to the
> non-digital world.
> >
> > Obviously, we have our data journalism example, but we seem to ignore.
> I
> > think that we ignore it because:
> > - it does not focus on changing things
> > - it is not precise about how information is published/access,
> > - it is quite long
> > (I liked what Simon proposed for this example [2] and this inspired me
> here)
> >
> >
> > To unblock the situation, I have:
> > - drafted a smaller example [3], focusing on a file being updated
> > - tried to illustrate examples of IVPTs in this example
> > - highlighted an example of IVPT that I don't know how to handle.
> >
> > In this example, it would be good to see
> > - where we have consensus
> > - where we have disagreement
> > - how we handle the outstanding example (i0) of IVPT
> >
> > Feedback by email or on wiki welcome!
> >
> > Cheers,
> > Luc
> >
> >
> > [1]
> http://lists.w3.org/Archives/Public/public-prov-wg/2011Jun/0096.html
> > [2]
> http://lists.w3.org/Archives/Public/public-prov-wg/2011Jun/0069.html
> > [3] http://www.w3.org/2011/prov/wiki/FileExample
> >
> > --
> > 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
> >
>
>
>