- From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
- Date: Mon, 14 Nov 2011 00:13:30 +0000
- To: Graham Klyne <GK@ninebynine.org>
- Cc: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, public-prov-wg@w3.org
On Sun, Nov 13, 2011 at 11:50, Graham Klyne <GK@ninebynine.org> wrote: > Generally, though, I think it is not a good idea to allow different accounts > to use the same URI for different entities. While accounts may contain > statemenbts that are specific to the account, they should also provide for > inferences about things (specifically, Entities) that hold outside the > context of an account; e.g. entity1 derivedfrom entity2, if true, should be > true independently of any account considered. We can't really enforce different provenance asserters to not make conflicting provenance assertions in different accounts - the possibility of this is just a fact of life. We can advice against it, but not prevent it. Just like you can't tell if I am now writing a secret book explaining about how Graham Klyne found the green Easter Bunny in the loft, you can't know that someone else is not making a contradictory provenance assertion about the URI which resource you are asserting something about. In RDF, if you are worried about this, you can counteract this by minting your own fresh URIs (which can deliberately be contradicted once they are known) or bnodes (which are unique per document/account, can't as easily be crashed, but then again can't be referred to from other provenance accounts of your own making). An account is just that, it's one "view", "understanding" or "guess" of how which things happened. Two different accounts might have a different understanding of what exactly <http://example.com/me> means - and therefore have a different kind of provenance trail. These accounts might or might not be reconsilable, and certainly doing so requires some isolation of the account assertions, using named graphs or other scoping, like the container() and account() structures in PROV-ASN. A good hint of what kind of understanding the two accounts have of the entity is by looking at their attributes, but ultimately there are still no guarantees that they are truly talking about "the same thing", just like you can't truly be sure who I meant if I casually said something about "the prime minister". -- Stian Soiland-Reyes, myGrid team School of Computer Science The University of Manchester
Received on Monday, 14 November 2011 00:14:27 UTC