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Re: Towards PROV-O Accounts

From: Jim McCusker <mccusj@rpi.edu>
Date: Thu, 5 Jan 2012 08:51:41 -0500
Message-ID: <CAAtgn=RmnJ0BFrokHTUFj4djjj+-XTnFC8TON5LB3rL3CYtFBw@mail.gmail.com>
To: Graham Klyne <GK@ninebynine.org>
Cc: Timothy Lebo <lebot@rpi.edu>, Provenance Working Group WG <public-prov-wg@w3.org>
Graham,

I disagree, mostly because there is an emphasis in RDF and Linked Data
now that what matters is the content, not the format. RDF graphs are
currently being served up in multiple alternative representations at
once. How do we best relate them, and why should I have to know
exactly which file Tim signed to be able to verify what he said?
Getting abstract graph identities and relating them to more concrete
representations (serializations and specific copies) is actually quite
easy [1]. The signer can then sign whatever they are comfortable with
and the relationships between serializations and abstract graphs can
be used to verify the signatures.

Jim

[1] http://purl.org/twc/pub/mccusker2012parallel and
https://github.com/timrdf/csv2rdf4lod-automation/raw/master/doc/publications/mccusker2012parallel.pdf

On Thu, Jan 5, 2012 at 3:34 AM, Graham Klyne <GK@ninebynine.org> wrote:
> Hi Tim,
>
> I took a quick look at this (your [1]), and I was OK with the basic
> structure used, but I'm not understanding why there is so much focus on a
> name for the abstract triples as opposed to a user-supplied name.
>
> I'm guessing this may be related to a similar issue with digital signatures
> over RDG graphs.  There has been work to apply such signatures to some
> canonicalization or abstraction of the graph, but I don't see the necessity.
>  In the real world, when one signs a document, one signs a *particular
> rendering* of the document, and said signature can be used as evidence for
> agreement to the abstract content of same.
>
> I see something similar applying to account graph assertions:  if a user
> asserts an account graph, they assert a *particular instance* (or maybe
> several) of that graph.  If one trusts that user, then one may license
> inferences based on the abstract content of the graph, and by extension
> inferences based on semantically equivalent graph instances, but that's a
> separate issue IMO.
>
> Why do I care about this?  I think that the essential nature of using named
> graphs to control the scope of what provenance accounts are actually being
> asserted (or treated as asserted for some purposes of provenance analysis)
> is confused and muddied by the discussion of different graph instances and
> abstract graph content.
>
> #g
> --
>
> PS: I don't know if it's at all relevant, but I made some personal notes a
> long time ago about issues around using contexts for scoping assertions:
>
>  http://www.ninebynine.org/RDFNotes/UsingContextsWithRDF.html
>
> (It's kind of dated now; I use the term "formulae", from Notation3, to mean
> roughly what we mean by named graphs.)
>
>
>
> On 05/01/2012 03:35, Timothy Lebo wrote:
>>
>> prov-wg,
>>
>> I have been working on some discussion [1] that is relevant to modeling
>> Accounts in PROV-O.
>>
>> It is incomplete, but I think ready for some initial feedback.
>>
>> Modeling accounts is on the agenda for tomorrow's telecon [2], so I hope
>> this can provide some discussion material.
>>
>> Regards,
>> Tim
>>
>> [1] http://www.w3.org/2011/prov/wiki/Using_graphs_to_model_Accounts
>> [2] http://www.w3.org/2011/prov/wiki/Meetings:Telecon2012.01.05
>>
>>
>>
>
>



-- 
Jim McCusker
Programmer Analyst
Krauthammer Lab, Pathology Informatics
Yale School of Medicine
james.mccusker@yale.edu | (203) 785-6330
http://krauthammerlab.med.yale.edu

PhD Student
Tetherless World Constellation
Rensselaer Polytechnic Institute
mccusj@cs.rpi.edu
http://tw.rpi.edu
Received on Thursday, 5 January 2012 13:52:31 UTC

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