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Re: PROV-ISSUE-200: Section 6.3 (PROV-DM as on Dec 5) [prov-dm]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Wed, 15 Feb 2012 12:12:26 +0000
Message-ID: <EMEW3|1cb53b9f363a4560ea80a8bfa167229co1ECCY08L.Moreau|ecs.soton.ac.uk|4F3BA12A.5040603@ecs.soton.ac.uk>
To: Satya Sahoo <satya.sahoo@case.edu>
CC: public-prov-wg@w3.org
Hi Satya,
This is issue is now closed.
Luc

On 02/14/2012 10:54 PM, Satya Sahoo wrote:
> Hi Luc,
> I am fine with closing this particular issue (I will be raising issues 
> against the TPWD separately).
>
> Thanks.
>
> Best,
> Satya
>
> On Thu, Dec 8, 2011 at 6:04 AM, Luc Moreau <L.Moreau@ecs.soton.ac.uk 
> <mailto:L.Moreau@ecs.soton.ac.uk>> wrote:
>
>     Hi Satya,
>
>     This is again *very frustrating*. This PROV-ISSUE-50, and your last
>     communication on this dates back from October 2nd!!!!
>
>     http://lists.w3.org/Archives/Public/public-prov-wg/2011Oct/0007.html
>
>     You have not responded to my message on Oct 3rd
>     http://lists.w3.org/Archives/Public/public-prov-wg/2011Oct/0009.html
>     and November 30th
>     http://lists.w3.org/Archives/Public/public-prov-wg/2011Nov/0419.html
>
>     Further comments below.
>
>     On 12/07/2011 02:22 AM, Provenance Working Group Issue Tracker wrote:
>
>         PROV-ISSUE-200: Section 6.3 (PROV-DM as on Dec 5) [prov-dm]
>
>         http://www.w3.org/2011/prov/track/issues/200
>
>         Raised by: Satya Sahoo
>         On product: prov-dm
>
>         Hi,
>         The following are my comments for Section 6.3 of the PROV-DM
>         (as on Dec 5):
>
>         Section 6.3
>         1. Given:
>
>         "An information flow ordering record is a representation that
>         an entity was generated by an activity, before it was used by
>         another activity."
>
>         How does the constraint:
>
>         "Given two activity records denoted by a1 and a2, if the
>         record wasInformedBy(a2,a1) holds, then the following temporal
>         constraint holds: the start event of the activity record
>         denoted by a1 precedes the end event of the activity record
>         denoted by a2."
>
>         make sense?
>
>         Detailed comment: Let us consider the scenario: "a chemical
>         reagent r1 was generated by activity a1 in September 2011" and
>         "r1 was used by researcher in experiment activity a2 in
>         December 2011". From a provenance perspective, we simply state
>         r1 was generated before it was used - where is the relevance
>         of activity ordering in above scenario (entity was generated
>         before it was used)?
>
>     you will note that the above constraint is a necessary condition
>     and not a sufficient condition!
>
>     The point about information flow ordering is that the entity does
>     not have to be explicitly mentioned.  It's an existential
>     quantifier over an entity.
>
>     If you activity a1 had started after the end of a2, it would have
>     been impossible to have this entity r1 generated by a1 and used by a2.
>
>         Further, activity ordering is important in provenance from a
>         very different perspective - "analyzing provenance of bank
>         transactions to justify penalty fee for customer c1 - the
>         $100.00 deposit activity da1 took place before or after $80.00
>         withdrawal activity wa1 happened in account with starting
>         balance of $5.00". So, if da1 happened before wa1 there should
>         not be any penalty fee, otherwise customer has to pay fee for
>         withdrawing more money than was available in the account.
>
>
>     This example is handled by having various account entities for the
>     various balances.
>     I don't think we need an explicit activity ordering here.
>
>         Clearly, the informedBy property does not address the
>         requirement of activity ordering for provenance. In addition,
>         the current definition of informedBy for representing whether
>         entity was generated before it was used does not need activity
>         information - it can be asserted either in terms of event
>         ordering or temporal ordering. I believe we should remove
>         wasInformedBy or move it out of activity ordering section.
>
>
>     What do you mean by *clearly*?
>     How can we assert this by event/temporal ordering ?
>     1. The relations precedes/follows do not belong to the data model
>     (they are used in interpretation)
>     2. The interpretation over wasInformedBy is a necessary condition,
>     not a sufficient condition.
>               There needs to be an entity used and generated between
>     these activities, though we dont have to assert it.
>
>
>         2. "The relationship wasInformedBy is not transitive. Indeed,
>         consider the records wasInformedBy(a2,a1) and
>         wasInformedBy(a3,a2), the record wasInformedBy(a3,a1), may not
>         necessarily hold, as illustrated by the following event line."
>
>         Comment: It is not clear from the description and the figure,
>         why wasInformedBy is not transitive? It is difficult to
>         interpret the figure without additional description.
>
>
>     Tim mentioned this. THis will be dealt with.
>
>         3. "Given two activity records identified by a1 and a2, the
>         record wasStartedBy(a2,a1) holds if and only if there exist an
>         entity record identified by e and some attributes gAttr and
>         sAttr, such that wasGeneratedBy(e,a1,gAttr) and
>         wasStartedBy(a2,e,sAttr) hold."
>
>         Comment: The above definition and related example for
>         wasStartedBy are not clear at all. What is meant by the
>         statement that "spawn-request" was generated by a1 and
>         "spawn-request" is in a wasStartedBy relation with a2, hence
>         a1 and a2 also have a wasStartedBy relation? Is
>         "spawn-request" supposed to represent control message
>         exchanged between a1 and a2 or something else?
>
>
>     There were problems in the text. I hopefully fixed them. Can you
>     check?
>
>     Luc
>
>         Thanks.
>
>         Best,
>         Satya
>
>
>
>
>
>     -- 
>     Professor Luc Moreau
>     Electronics and Computer Science   tel: +44 23 8059 4487
>     <tel:%2B44%2023%208059%204487>
>     University of Southampton          fax: +44 23 8059 2865
>     <tel:%2B44%2023%208059%202865>
>     Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
>     <mailto:l.moreau@ecs.soton.ac.uk>
>     United Kingdom http://www.ecs.soton.ac.uk/~lavm
>     <http://www.ecs.soton.ac.uk/%7Elavm>
>
>
>

-- 
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 Wednesday, 15 February 2012 12:12:58 GMT

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