- From: McBride, Brian <bwm@hplb.hpl.hp.com>
- Date: Fri, 5 Jan 2001 12:28:57 -0000
- To: "RDF Interest (E-mail)" <www-rdf-interest@w3.org>
- Cc: "'Graham Klyne'" <GK@Dial.pipex.com>
Hi Graham, > I've started an HTML document with these in. In reification > of a graph, > would you allow "collection" rather than "bag", to allow some > wiggle room > in the exact representation? Right now, I'd probably say it should be a bag, but thats not as negative as it sounds. I think its important to position this concept relative to the context concept you have been championing. I divide these discussions into two tracks: o clarifying the current specs o future developments The reification of a graph concept to me is in the clarifying the current specs track. To me, contexts are an important new development. I believe that contexts have extra semantics over just being a collection of statements, that they need the machinery of the logic layer - interpretations and that sort of thing to do them properly. The RDF layer alone does not have the machinery - all it can do are collections of statements. So in terms of the RDF layer, a graph is an unordered collection of statements. BAG is the right construct for representing that. SEQ and ALT just don't make sense. Further, m&s talks about description elements representing bags of reified statements which maps nicely onto the language that those bags and their contents are the reifications of the subgraphs defined by a description element. I share your concerns about the current definitions of bags - have ordered properties for the members of an unordered collection just seems bizare to me. So I'd be sympathetic to a future spec defining improved collections. But right now BAG is what we have, so in terms of working with the current spec, I think BAG is right. Contexts will bring a much richer and powerful semantics. Brian > > #g > -- > > > >How about: > > > >RDF Graph: > > > > a set of RDF statements. > > > >Reification of an RDF Graph > > > > A bag containing the reifications of the statements in > the RDF graph > > > >Reified Graph > > > > The bag in the reification of an RDF graph. > > > >Brian > > > > > -----Original Message----- > > > From: Graham Klyne [mailto:GK@Dial.pipex.com] > > > Sent: 01 January 2001 17:32 > > > To: Bill de hÓra > > > Cc: RDF-IG > > > Subject: Re: RDF Terminologicus > > > > > > > > > OK, here's my shot: > > > > > > > > > Web Resource: > > > Anything that is identified by a URI [RRC2396]. > > > > > > RDF Resource: > > > [See RDF M&S section 5] Note that an RDF resource is not > > > necessarily a > > > web resource, > > > though any web resource can be an RDF > > > resource. Consider: http://foo.com/#a and > > > http://foo.com/#b name distinct RDF resources, but not > > > distinct web > > > resources. > > > > > > RDF Statement, Statement: > > > [See RDFM&S section 5] > > > > > > RDF Description: > > > [See RDFM&S] > > > Construct containing representations of a number of > RDF statements > > > about a specific RDF resource, and possibly some > > > additional statements. > > > > > > Description [of]: > > > (As opposed to RDF Description) > > > Language or data structure providing information about > > > some entity or > > > concept. > > > > > > Stand for: > > > A labelled entity that is used in descriptions indicate > > > some entity or > > > concept. > > > > > > Reification (of a statement): > > > [See RDFM&S section 5] A resource that stands for the > statement > > > together with > > > the four statements that describe the statement. In my > > > opinion, a > > > reification of > > > a statement is not unique: there may be more than one > > > reification of > > > any given > > > statement. > > > > > > Representation: > > > A data structure (abstract or concrete) that captures some > > > essential > > > properties of some entity or concept. > > > > > > Representing [x]: > > > Being a representation of [x] (see above) > > > > > > Context: > > > An environment within which some statements are taken > to be true. > > > > > > Quoting: > > > A reference to a statement without necessarily making any > > > assertion about > > > its truth or falsity. > > > > > > Stating: > > > An assertion that some statement is true in some context. > > > (or should that be: > > > An assertion in some context that some statement is true. > > > ?) > > > NOTE: this assertion is a statement separate from the > > > statement asserted to be true. > > > > > > Model: > > > (I've tried to stop using this term, since it has a > quite specific > > > meaning to logicians, that is not the same as what I would > > > regard as > > > its "natural" meaning.) > > > > > > > > > #g > > > ------------ > > > Graham Klyne > > > (GK@ACM.ORG) > > > > > ------------ > Graham Klyne > (GK@ACM.ORG) >
Received on Friday, 5 January 2001 07:29:06 UTC