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Re: combination of RDF* and graph-level metadata (named graphs)

From: Olaf Hartig <olaf.hartig@liu.se>
Date: Fri, 30 Aug 2019 10:36:10 +0000
To: Dan Brickley <danbri@google.com>
CC: "public-rdf-star@w3.org" <public-rdf-star@w3.org>, David Booth <david@dbooth.org>
Message-ID: <bcd2d0ac-88a9-4ee9-ab6e-66ba4d663df0.maildroid@localhost>
Dan,

I'm not sure I understand. What do you mean by "graph edges"?

Is your idea to use an RDF* triple to capture something like, e.g., "the graph denoted by IRI ex:mygraph contains the edge/triple (ex:Bob, foaf:knows, ex:Alice)." ?

Olaf 

-----Original Message-----
From: Dan Brickley <danbri@google.com>
To: Olaf Hartig <olaf.hartig@liu.se>
Cc: "public-rdf-star@w3.org" <public-rdf-star@w3.org>, David Booth <david@dbooth.org>
Sent: Fri, 30 Aug 2019 12:05
Subject: Re: combination of RDF* and graph-level metadata (named graphs)

Quick thought: we could also potentially use rdf* annotations to attach
multiple graph edges to a named graph. That feels slightly less heavyweight
than classical named graphs, although maybe the difference is trivial?

Dan

On Fri, 30 Aug 2019, 08:52 Olaf Hartig, <olaf.hartig@liu.se> wrote:

> David,
>
> On torsdag 29 augusti 2019 kl. 14:14:39 CEST David Booth wrote:
> > [...]
> > My main concerns:
> >
> >   - It must be easy to make statements about an entire graph -- a set of
> > triples -- rather than one triple at a time.  At present RDF* does not
> > allow this, but my understanding is that it could be extended to do so.
> > IMO this is critically important.
>
> I don't see why this would be necessary; I mean, I don't think we need
> another
> such approach. The approaches that you mention below (named graphs, as a
> data
> model feature, and the N3 syntax to talk about graphs) already give us the
> means to make statements about an entire graph. Therefore, in contrast to
> these approaches, RDF* focuses on making statements about individual
> triples
> (similar to standard RDF reification and edge properties in Property
> Graphs).
>
> Making statements about entire graphs and making statements about
> individual
> triples are orthogonal issues. Of course, there are use cases in which we
> want
> to be able to do both within the same dataset. To this end, the concept of
> a
> named graph may simply be extended to be a pair consisting of an IRI (the
> graph name) and an RDF* graph (rather than an RDF graph). Then, it is
> possible
> to use the IRI to make statements about the graph as a whole, and within
> the
> graph you may have (nested) RDF* triples to make statements about some
> particular triple.
>
> >   - It should be harmonized with other existing mechanisms, such as
> > named graphs and N3's ability to talk about graphs.
>
> Does the approach outlined above (named RDF* graphs) address this concern?
>
> Olaf
>
>
> > Thanks!
> > David Booth
>
>
Received on Friday, 30 August 2019 10:36:40 UTC

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