- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Tue, 31 Jan 2012 09:29:06 +0000
- To: public-prov-wg@w3.org
Hi Graham, On 01/30/2012 11:01 AM, Provenance Working Group Issue Tracker wrote: > PROV-ISSUE-230 (Name-scoping): Name scoping in DM is wrong concept [prov-dm] > > http://www.w3.org/2011/prov/track/issues/230 > > Raised by: Graham Klyne > On product: prov-dm > > The PROV-DM draft introduces name scoping, particularly with respect to Accounts. > > I think this is the wrong concept, as it tries to use name-scoping to capture different provenance accounts about the same entity. I think that an entity id should refer to the same Entity wherever it occurs. What may vary between accounts is the claims that are made about that entity. Without this, I see no basis for comparing accounts. > > For PROV-DM, I imagine one one might say that the account+local id together form the common identifier (ala compound key), but then I think some additional mechanism would then be needed to link names from different accounts. > > When the names used are URIs, then I think that the notion of scoping is entirely wrong. URIs are, by design, a *global* namespace, and it creates confusion (or worse) of one allows a URI to denote different things. Personally, I would not prescribe the form of names used by the DM; the use of URIs is a syntactic matter, and as such it could be introduced for ASN. > What is scoped is what we say about entities: e.g. - what is said about entity e1 in acc1 differs/is simlar/is specialisation of /... of what is said about entity e2 in acc2. - the entity e1 as described in acc1 was generated by the activity a2 as described in acc2 We may not like the notion of scope but recognizing that account+local id forms a key, in effect, constitutes a notion of scope. The crucial thing is to be clear about what is scoped (and I agree that the document is not clear, given all the contradictions about identifiers I have raised and that we are trying to address now, cfr ISSUE-183). > I see the DM as an "abstract syntax" in the sense proposed by John McCarthy, where the terms and productions have the form of logical predicates, and in particular a "name" is distinguished simply as a predicate "Name(id)" which is True iff "id" is a name. This avoids any need to prescribe the actual form of referenced by the DM. > > > > BTW, the DM states that names are 'qualified names': I think this is important because, namespacing is part of the abstract model I believe. Luc -- 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
Received on Tuesday, 31 January 2012 09:29:39 UTC