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Re: Contextualization ---> Optional bundle in Specialization

From: Satya Sahoo <satya.sahoo@case.edu>
Date: Wed, 27 Jun 2012 18:00:21 -0400
Message-ID: <CAOMwk6xSs5bUxEkyQ1BCS4OmdJDgssrw+KQA5RQygvXPTVJu-Q@mail.gmail.com>
To: James Cheney <jcheney@inf.ed.ac.uk>
Cc: Graham Klyne <graham.klyne@zoo.ox.ac.uk>, Luc Moreau <L.Moreau@ecs.soton.ac.uk>, Provenance Working Group WG <public-prov-wg@w3.org>
Hi James,
Guha's thesis (along with McCarthy's generality in AI) were my primary
reasons for objecting to Accounts earlier -

Yes, that worries me too.  I have read over a bit of Guha's thesis.  Things
> get complicated quickly, though (unlike Guha) at least we do not
> contemplate having the syntax of formulas to depend on the context (if we
> think bundles are contexts).

If bundles are contexts then bundles allow us to make non-monotonic
statements, while RDF semantics is strictly monotonic.


>  So, more standard semantic structures from modal logic "ought to work"
> (famous last words).
>
> To me, adding something complicated at the last minute is not a good idea
> (invoking Hoare again).  It can always be added later when it is well
> understood, but if we add something broken now we're stuck with it forever.
>  Maybe a good compromise is to add the syntax (and saying how/why people
> might use it) without pretending to have a semantics or constraints.
>
> +1

Best,
Satya


> --James
>
> On Jun 27, 2012, at 12:24 PM, Graham Klyne wrote:
>
> > James,
> >
> > I think I said something in the IRC chat for the face-to-face meeting,
> but I'll try and reconstruct it here for the record.  I think your attempt
> at formalizing contexts is very useful, if only because it helps to show
> how tricky a problem this is.
> >
> > One thing that comes out clearly to me from your semantics is that
> capturing the semantics of contextualization (at least in your approach,
> and I suspect in any possible way that addresses the motivating use-case)
> requires semantics that goes beyond the expressive capability of current
> RDF semantics.  The current RDF semantics has no capacity for dealing with
> multiple worlds - it depends on a single interpretation mapping that
> applies to all terms used in an RDF expression (graph), and has no way to
> link the semantics of disparate RDF expressions.
> >
> > As I understand it, the RDF dataset structure provides a syntactic
> framework to support richer semantics, but as far as I can tell there are
> not yet any actual semantics defined for it.
> >
> > #g
> > --
> >
> > On 27/06/2012 16:32, James Cheney wrote:
> >> Hi,
> >>
> >> Neither of those readings below make sense to me...
> >>
> >> I thought the definition of contextualization before was:
> >>
> >> An entity that is a contextualization ◊ of another entity presents all
> aspects of the latter as per the latter's description in another bundle
> (referred to as remote bundle), and therefore constitutes a particular case
> of specialization of the latter entity.
> >>
> >> Your new text in describing the bundle argument to specializationOf
> just says this:
> >>
> >> bundle: an optional identifier (b) of a bundle that contains a
> description of supra and further constitutes one additional aspect
> presented by infra.
> >>
> >> and this is saying something completely different to: now the bundle is
> an aspect, rather than the context that includes aspects that we claim e2
> also has.  It's not that clear to me what this means (and there is no
> longer clarifying text about supra being described in the remote bundle b).
> >>
> >> I understand we want to avoid the word "context", but this seems to be
> both renaming and changing the meaning (to something new), which goes
> beyond what I thought we agreed.
> >>
> >> (I thought we had agreed to rename contextualization to something else,
> but expected that this would be a separate relation, not overloading
> specialization.  Should have asked.)
> >>
> >> FWIW, see also
> http://www.w3.org/2011/prov/wiki/FormalSemanticsWD5#Bundles which
> attempts to formalize what I thought contextualization was about.
> >>
> >> --James
> >>
> >> On Jun 27, 2012, at 9:52 AM, Luc Moreau wrote:
> >>
> >>> Hi James,
> >>>
> >>> Assuming we have a "top level" bundle (I am not sure what it would be
> exactly),
> >>> I don't think that the two expressions you are suggesting are
> equivalent.
> >>>
> >>> specializationOf(e1,e2,toplevelBundle)
> >>>
> >>> indicates that e1 shares all aspects of e2 and presents a further
> aspect: the bundle toplevelBundle.
> >>>
> >>>
> >>> specializationOf(e1,e2)
> >>>
> >>> indicates that e1 shares all aspects of e2 and presents and further
> specific aspects (but without
> >>> indicating which ones): a bundle MAY or MAY NOT have been fixed.
> >>>
> >>> Luc
> >>>
> >>> On 06/27/2012 02:57 PM, James Cheney wrote:
> >>>> Hi,
> >>>>
> >>>> I am happy with renaming contextualization to something less
> controversial, but renaming it to specialization seems (to me) confusing,
> unless it's clear that the semantics of the two variants are compatible.
> >>>>
> >>>> Do we have a name for the "top level" bundle in PROV (i.e., the
> anonymous bundle that contains the toplevel expressions), and supposing we
> do, is
> >>>>
> >>>> specializationOf(e1,e2)
> >>>>
> >>>> equivalent to
> >>>>
> >>>> specializationOf(e1,e2,toplevelBundle)
> >>>>
> >>>> ?
> >>>>
> >>>> --James
> >>>>
> >>>> On Jun 27, 2012, at 4:49 AM, 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
> >>>>>
> >>>>> --
> >>>>> 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
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >>
> >> The University of Edinburgh is a charitable body, registered in
> >> Scotland, with registration number SC005336.
> >
>
>
> --
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>
>
Received on Wednesday, 27 June 2012 22:00:52 UTC

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