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Re: PROV-ISSUE-183 (prov-dm-identifiers): identifiers in prov-dm [prov-dm]

From: Jim McCusker <mccusj@rpi.edu>
Date: Thu, 5 Jan 2012 12:27:10 -0500
Message-ID: <CAAtgn=S7OCL-LMqKDr78SHaWaQDp2AgibTcy0QGS_njT=6GyHA@mail.gmail.com>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Cc: public-prov-wg@w3.org
I'm confused by item 3. Let me lead off with my understanding of how
identifiers in DM relate to resources in RDF:

Resources can be identified using URIs, in which case the resource has
a "global scope", that is, any assertions that use that URI are, by
definition, discussing the same referent. Blank nodes, or anonymous
resources, are locally scoped to the RDF document. As of RDF 1.1,
bnodes can be skolemized, which means they can have a name that is
stable across queries and multiple serializations. I see these as
corresponding to identifiers with local scope in the PROV-DM.

The rest of my comments are interleaved.

On Wed, Dec 21, 2011 at 4:08 PM, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:

> 3. Constraint:
> http://dvcs.w3.org/hg/prov/raw-file/default/model/ProvenanceModel.html#identifiable-record-in-account
>  requires that for a given entity identifier there is a most one entity
> record containing this identifier.

This cannot be true of URIs, as we maintain the AAA principle (Anyone
can say Anything about Any subject).

> We believe that with the following:
> - entity identifiers can be URIs with the usual semantic web understanding
> - entity identifiers do *not* double up as URI for entity records

I'm not sure why this is a requirement. This greatly complicates
representations in RDF. Rather than saying:

:writingThisEmail prov:wasControlledBy rpi:JimMcCusker.

I would have to say:

:writingThisEmail prov:wasControlledBy :jim.
:jim prov:identifier rpi:JimMcCusker.

Which makes no sense, because URIs directly denote the things in the
world that we wish to denote in a provenance graph.

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

PhD Student
Tetherless World Constellation
Rensselaer Polytechnic Institute
Received on Thursday, 5 January 2012 17:28:05 UTC

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