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Re: Contextualization ---> Optional bundle in Specialization

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Wed, 27 Jun 2012 22:19:15 +0100
Message-ID: <EMEW3|b44c87807629fe9687bad03e9ac7afaao5QMJH08L.Moreau|ecs.soton.ac.uk|4FEB78D3.5070508@ecs.soton.ac.uk>
To: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
CC: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Graham,

I don't understand what you are saying here. Please see below.

On 27/06/12 18:09, Graham Klyne wrote:
> On 27/06/2012 10:49, Luc Moreau wrote:
> > All,
> >
> > At the face to face meeting, we have agreed to rename 
> contextualization and mark
> > this feature
> > at risk. Tim, Stephan, Paul and I have worked a solution that we now 
> share with
> > the working group.
>
> I'm afraid I still have a problem with this.
>
> Considering your bundle tool:analysis01:
> [[
> bundle tool:analysis01
>     agent(tool:Bob-2011-11-16, [perf:rating="good"])
>     specializationOf(tool:Bob-2011-11-16, ex:Bob, ex:run1)
>
>     agent(tool:Bob-2011-11-17, [perf:rating="bad"])
>     specializationOf(tool:Bob-2011-11-17, ex:Bob, ex:run2)
> endBundle
> ]]
>
> The problem is that, if subject to RDF semantics for URI 
> interpretation, I can see no semantic distinction is possible between
>
>   tool:Bob-2011-11-16
> and
>   tool:Bob-2011-11-17
>
> I.e. they are both specializations of ex:Bob, and that is all we can 
> know about them, as (by the nature of the semantics of URI 
> interpretation) the denotation of ex:Bob that appears in ex:run1 is 
> the same as the denotation of ex:Bob that appears in ex:run2.
>

Are you trying to say that if

specializationOf(luc-in-boston,luc)
specializationOf(luc-in-soton,luc)

You cannot see any semantic distinction between luc-in-boston and 
luc-in-soton?????
Surely, there is a difference!

Likewise, tool:Bob-2011-11-16 and tool:Bob-2011-11-17 can be 
distinguished by the additional aspect
they present (bundle ex:run1 or bundle ex:run2).

In this example, we have three different identifiers
ex:Bob
tool:Bob-2011-11-16
tool:Bob-2011-11-17
each with a single denotation: i.e. no denotation that is context specific.

I don't see what the issue is.

Luc




Luc

> ...
>
> I do, however, have a different compromise that provides a hook for 
> introducing possible semantics later, or in private implementations, 
> without sneaking in something that could well turn out to be 
> incompatible with, or just different than, what the RDF group may do 
> for semantics of datasets.
>
> The hook is this: simply allow attributes for the specializationOf 
> relation, but don't define a specific attribute for bundle.  This 
> would allow you to do a private implementation of the scheme you 
> describe, but would not allow it to be mistaken for something that has 
> standardized semantics.  As in:
>
>   specializationOf(tool:Bob-2011-11-17, ex:Bob,
>                    [myprivateattribute:bundle=ex:run2])
>
> ...
>
> In case you think I'm jumping at shadows here, I'll note that RDF has 
> been here before.  The original 1999 RDF specification described 
> reification without formal semantics.  Reification was intended to 
> allow for capturing this kind of information - i.e. to make assertions 
> about context of use, etc - a kind of proto-provenance, if you like.  
> But when the group came to define a formal semantics for RDF, there 
> were two possible, reasonable and semantically incompatible 
> approaches; looking at the way that reification was being used "in the 
> wild", it turned out that there was data out there that corresponded 
> to both of these (incompatible) approaches.  This was in the very 
> early days of the semantic web, so the harm done was quite limited.  I 
> think a similar mistake today would cause much greater harm.
>
> I think the appropriate way forward is to take this tool performance 
> analysis use-case to the RDF-PROV coordination group, and ask that it 
> be considered as input when defining semantics for RDF datasets.  I 
> would expect that whatever semantic structure they choose, it should 
> be able to accommodate the use-case. Then, we should be better placed 
> to create an appropriate and compatible contextualization semantics 
> for provenance bundles.  But until then, I think we invite problems by 
> trying to create a standardized data model structure without 
> standardized RDF-compatible semantics to accommodate this use-case.
>
> #g
> -- 
>
> Tracker, this is ISSUE-385
>
> On 27/06/2012 10:49, Luc Moreau wrote:
>> All,
>>
>> At the face to face meeting, we have agreed to rename 
>> contextualization and mark
>> this feature
>> at risk. Tim, Stephan, Paul and I have worked a solution that we now 
>> share with
>> the working group.
>>
>> Given that contextualization was already defined as a kind of 
>> specialization, we
>> now allow an optional
>> bundle argument in the specialization relation. (Hence, no need to 
>> create a new
>> concept!)
>>
>> See section 5.5.1 in the current Editor's draft
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#term-specialization 
>>
>>
>> Feedback welcome.
>>
>> Regards,
>> Luc
>>
>> PS. Tracker, this is ISSUE-385
>>
Received on Wednesday, 27 June 2012 21:19:44 UTC

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