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Re: proposed responses to public comments (deadline: Wednesday 10/10)

From: James Cheney <jcheney@inf.ed.ac.uk>
Date: Thu, 11 Oct 2012 13:53:24 +0100
Cc: public-prov-wg@w3.org
Message-Id: <21BD3CA7-BBE1-4A91-804D-41DDA3F949A7@inf.ed.ac.uk>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Hi,

I don't think the proposed inference rule is necessarily wrong (though I haven't thought about its impact on termination). But the original issue wasn't suggesting this, only saying that we should make the intended meaning of alternate clearer.

This is similar to the discussion we had (maybe back in February/earlier?) about whether "things" are explicit in the model, or just entities.  If our response makes clearer that two "alternateOf" entities have in common is that they present aspects of a common thing (perhaps separated in time), this does not necessarily require that the provenance explicitly include a single entity subsuming the two alternate entities.  

It's the notion of "underlying thing" that I suspect is going to cause the greatest confusion, since we don't explicitly model the things or relations between entities and things, and a casual reader is likely to think entity = thing.  

Perhaps the response can also say that alternate is non-core precisely because it is a subtle issue that many users won't need to care about; as far as I am aware there are no negative consequences to failing to assert that two entities are alternates, only inferences that we won't be able to make.  (Even then, alternate is currently a bit of a white elephant.)

Simon, would you agree with the following revision (which avoids conflating specialization with the relationship between entity and thing):

Note that alternateOf is a necessarily very general relationship that, in reasoning, only tells you that the two alternate entities fix different aspects of some common thing (possibly evolving over time), and so there is some relevant connection between the provenance of the alternates. In a specific application context, alternateOf, or a subtype of it, could allow you to infer more. The alternateOf relation is provided mainly for complex scenarios involving things that change over time, and is not one of the core relationships that casual users of PROV will employ routinely.  

--James

On Oct 11, 2012, at 1:31 PM, Luc Moreau wrote:

> Hi Simon and James
> 
> In response to your comment for ISSUE-526,
> I have no objection with adding this sentence, however, I am not sure that prov-constraints currently says that.
> 
> James, what is your view on this?
> 
> specializationOf(e2,e1) implies alternateOf(e2,e1)
> 
> but I don't think we have that
> 
> alternateOf(e2,e1) implies there exists e such that specializationOf(e2,e) and specializationOf(e1,e)
> 
> So, by adding Simon's sentence, aren't we saying more than what prov-constraints specifies.
> Vice-versa, should Simon's statement be encoded in prov-constraints.
> 
> Luc
> 
> On 10/09/2012 04:12 PM, Miles, Simon wrote:
>> Hello Luc,
>> 
>> Responses to responses...
>> 
>> 
>> 
>> ISSUE-526:
>> The response is OK, but I wonder if an honest answer to the original question is that alternateOf is a necessarily very general relationship that, in reasoning, only tells you that there is something that the two alternates are both specializations of, and so there is some relevant connection between the provenance of the alternates. In a specific application context, alternateOf, or a subtype of it, could allow you to infer more.
>> 
>> 
>> 
>> Dr Simon Miles
>> Senior Lecturer, Department of Informatics
>> Kings College London, WC2R 2LS, UK
>> +44 (0)20 7848 1166
>> 
>> Transparent Provenance Derivation for User Decisions:
>> http://eprints.dcs.kcl.ac.uk/1400/
>> ________________________________________
>> From: Luc Moreau [l.moreau@ecs.soton.ac.uk]
>> Sent: 08 October 2012 15:06
>> To: public-prov-wg@w3.org
>> Subject: proposed responses to public comments (deadline: Wednesday  10/10)
>> 
>> Dear all,
>> 
>> At
>> http://www.w3.org/2011/prov/wiki/ResponsesToPublicComments#PROV-DM_.28Under_Review.29,
>> please find our proposed responses to public comments:
>> - ISSUE-530
>> - ISSUE-520
>> - ISSUE-521
>> - ISSUE-522
>> - ISSUE-509
>> - ISSUE-526
>> - ISSUE-502
>> 
>> They will become the group responses unless we hear objects by Wednesday
>> 10/10.
>> 
>> 
>> Best regards,
>> Luc
>> 
>> PS. To help tracker, please include only the relevant issue number when
>> responding.
>> 
>> --
>> 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
> 
> -- 
> 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
> 
> 
> 


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Received on Thursday, 11 October 2012 12:53:52 GMT

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