- From: Timothy Lebo <lebot@rpi.edu>
- Date: Tue, 22 Nov 2011 12:53:06 -0500
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Cc: Graham Klyne <graham.klyne@zoo.ox.ac.uk>, Paul Groth <p.t.groth@vu.nl>, Stephan Zednik <zednis@rpi.edu>, Provenance Working Group WG <public-prov-wg@w3.org>
On Nov 10, 2011, at 12:34 PM, Luc Moreau wrote: > Hi Graham, > > My very original idea was to use Strings for roles, because some (non-SW) users > may just want to use a string to say "person". > > My second idea was also to allow URIs, which is what the SW people would have used. > e.g. "foaf:person" > > Beyond roles, parameter positions may also be encoded as an index. > > Hence, the choice of typed literal. They do have fixed denotations. > > I felt this was enough. I still feel this is enough. > > The Prov-O team would have had the flexibility to translate a prov-dm Literal to whatever > they felt appropriate. As long as this is explicit (it is in the latest draft), then DM is providing the flexibility that PROV-O needs. > > But feedback indicated that it was not. The feedback was "It is not clear that we can make URIs out of DM's literals - we are worried that we can only make RDFS Literals" But the statements in DM make it clear that we can. "A PROV-DM Literal represents a value whose interpretation is outside the scope of PROV-DM." "in either case; such URI has no specific interpretation in the context of PROV-DM." -Tim > So, where are we standing on this? > We can close this issue. -Tim > Luc > > > > On 11/10/2011 02:25 PM, Graham Klyne wrote: >> On 06/11/2011 19:04, Paul Groth wrote: >>> This is where the confusion is. Literals in RDF-speak are not URIs. Maybe a note in either prov-o or prov-dm would help clarify this. >> >> Yes. >> >> Referring to the model theoretic style of semantics used for RDF (and also for formalizing first order logic - if DM is appealing to some different semantic framework, this needs to be spelled out): >> >> Specifically literals have a fixed denotation. A plain string denotes itself. In integer literal denotes the number determined according to the numeric encoding scheme, a URI literal denotes a URI (*), etc... >> >> By contrast, names (i.e. URIs in RDF) denote whatever some "interpretation" says they denote. This interpretation is just a function from names to things, which is not fixed by the language. The associated semantics (inherent and/or additionally defined) constrain the interpretations that are considered valid (also known as "models"). >> >> What this all means is that if something is a literal, you can't arbitrary say it denotes the American president known as "Barack Obama" (unless such a mapping is baked into an underlying literal structure, which doesn't really make sense). >> >> Where this all leads is that I think the roles in DM should be names, not literals. >> >> #g >> -- >> >> (*) ... as opposed to a URI-node in RDF, which denotes whatever the applicable interpretation says it denotes. >> > > -- > 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, 22 November 2011 17:54:12 UTC