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Re: [httpRange-14] What is an Information Resource?

From: Ian Davis <lists@iandavis.com>
Date: Wed, 30 Jan 2008 14:19:51 +0000
To: "Sean B. Palmer" <sean@miscoranda.com>
Cc: www-tag@w3.org
Message-Id: <1201702791.13362.70.camel@iand-laptop>


On Sat, 2007-12-15 at 17:40 +0000, Sean B. Palmer wrote:
> Xiaoshu Wang gave a list of things recently and asked which ones are
> information resources, but didn't receive a reply. I'm going to use
> this opportunity to answer that question using what I've learned from
> last week's threads, to summarise and elucidate.
> 
> We can start by discarding Webarch's faulty definition. Ian Davis
> asked Tim on IRC whether an RDF Graph is an information resource [1],
> and Tim replied "no". This is consistent with how CWM implements the
> web, relating an IR to its Graph using the log:semantics property. But
> it's not consistent with Webarch's definition that "all of their
> essential characteristics can be conveyed in a message", because all
> of a Graph's essential characteristics can be conveyed in a message
> and yet it is not an IR.
> 

As an additional data point for this issue, today I noticed that the
SPARQL rec [2] says:

"The FROM and FROM NAMED keywords allow a query to specify an RDF
dataset by reference; they indicate that the dataset should include
graphs that are obtained from representations of the resources
identified by the given IRIs (i.e. the absolute form of the given IRI
references)."

and [3]:

"The FROM NAMED syntax suggests that the IRI identifies the
corresponding graph, but the relationship between an IRI and a graph in
an RDF dataset is indirect. The IRI identifies a resource, and the
resource is represented by a graph (or, more precisely: by a document
that serializes a graph)."

I think this is consistent with the view that graphs are information
resources that can serve representations of themselves (documents that
serialize the graph).

Taking the alternate view, that graphs are not information resources,
would suggest that SPARQL is conflating the URIs for graphs and their
serialized descriptions.


Ian

[2] http://www.w3.org/TR/rdf-sparql-query/#rdfDataset
[3] http://www.w3.org/TR/rdf-sparql-query/#namedGraphs
Received on Wednesday, 30 January 2008 14:22:09 UTC

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