Re: Requirements for a possible "RDF 2.0"

On Sat, Jan 16, 2010 at 9:52 AM, Peter Ansell <ansell.peter@gmail.com> wrote:
> Sorry, I hadn't read through the definition for blank node properly.
> If I had realised that Blank Nodes could actually represent anything,
> instead of my naive, incorrect, view that they were just placeholders
> for URI's. I do understand why Blank Nodes can't be put in the
> predicate position currently though.

They're placeholders in the sense that a URI is missing from the graph
at that point. But since URIs can (webarch tells us) name anything
too, your understanding might not have been too far off.

(aside)
RDF bNodes are a form of 'missing information'; in general, RDF makes
it possible to exchange information where you've got bits of it
missing, since we try to assemble a fuller picture by pulling together
fragments of the whole story from diverse sources. "Missing isn't
broken"(*), but sometimes it is nevertheless really really annoying.
Throwing a generated URI into the graph instead of leaving it nameless
(blank) makes it easier for others to attach properties at that point
in a subsequently super-imposed graph, although sometimes this comes
with unwelcome syntactic, privacy or other processing burden. I'm no
more pro-bNode than I am pro-ignorance, but it's often useful to be
able to mention things and focus on identifying them via their well
known properties, rather than their unknown URIs.

cheers,

Dan



(*) http://web.archive.org/web/20031003223643/http://rdfweb.org/mt/foaflog/archives/000047.html

Received on Saturday, 16 January 2010 09:24:25 UTC