W3C home > Mailing lists > Public > public-prov-wg@w3.org > June 2012

Re: Contextualization ---> Optional bundle in Specialization

From: Graham Klyne <Graham.Klyne@zoo.ox.ac.uk>
Date: Thu, 28 Jun 2012 12:25:29 +0100
Message-ID: <4FEC3F29.6050308@zoo.ox.ac.uk>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
CC: James Cheney <jcheney@inf.ed.ac.uk>, Timothy Lebo <lebot@rpi.edu>, Satya Sahoo <satya.sahoo@case.edu>, Provenance Working Group WG <public-prov-wg@w3.org>
On 28/06/2012 09:12, Luc Moreau wrote:
> Hi James,
> As far as your suggestion is concerned, this is mostly how Tim mapped
> Contextualization to prov-o.
> Some trade-offs are necessary. We can discuss them.
> However, I don't think it solves Graham's problem!

Actually, I think the proposal is not so far from an earlier proposal I made, 
which is to keep specializationOf and inBundle relations separate.  You objected 
to this because it led to conclusions like an entity being both slower *and* 
having good performance.  If I understand it correctly, James's proposal here 
would lead to similar conclusions (which I think he acknowledges by saying "I 
don't see how this addresses the original motivation for ctxOf").

My problem is that I don't think you can avoid that conclusion without a proper 
semantics of context, which RDF does not currently have.


> On 06/28/2012 04:35 AM, James Cheney wrote:
>> If all that we need is a way to be able to say "e2 is a specialization of e1
>> which is described in bundle b", then would the following suffice:
>> 1. Leave out ctxOf (or the 3-ary form of specializationOf)
>> 2. Add a special attribute "prov:inBundle" that any entity (or indeed anything
>> else) can have, linking each entity id to a bundle it appears in (there may be
>> more than one).
>> 3. Then instead of ctxOf(e2,e1,b) we just say specializationOf(e2,e1). The
>> fact that e1 happens to be in bundle b gets transferred by e2, along with all
>> other attributes. (Which seems weird to me, since e2 isn't explicitly
>> mentioned in b, but if being in a bundle is just an ordinary attribute, then
>> it should be transferred by specialization just like every other attribute).
>> I don't see how this addresses the original motivation for ctxOf, but don't
>> see that it does any harm - the complications arise if we start trying to
>> assign different meaning to "entity e" and "entity e in bundle b".
>> Just putting this out there - I am not pretending to understand that I
>> understand what ctxOf means at this point, and so the probability that I'm
>> barking up the wrong tree is high. But maybe finding out why this is wrong
>> will be educational.
>> --James
Received on Thursday, 28 June 2012 11:32:18 UTC

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