W3C home > Mailing lists > Public > semantic-web@w3.org > December 2007

Named RDF Graphs - A Warning

From: Sandro Hawke <sandro@w3.org>
Date: Tue, 18 Dec 2007 08:53:29 -0500
To: "Sean B. Palmer" <sean@miscoranda.com>
Cc: semantic-web@w3.org
Message-ID: <28383.1197986009@ubuhebe>


"Sean B. Palmer" <sean@miscoranda.com> writes:
> People will start using using HTTP URIs that return a 200 to identify
> RDF Graphs, whereas RDF Graphs are disjoint with information
> resources.  Think about what else you can get from an RDF/XML
> document: an XML infoset, a sequence of unicode characters.  The graph
> is not the document; it's not the information resource.

I think you're wrong here.  I understand where you're coming from, I
think, where log:semantics is a composite function (of getting *and*
parsing the document), but at the same time I do believe that in every
reasonable sense of Web Architecture, an RDF graph can be an information
resource.  Just like an image abstracted of serialization technology
(JPG vs GIF vs PNG) is a resource with multiple serializations (called
"representations" in WebArch), an RDF graph, abstracted of serialization
technology (RDF/XML vs N3 vs N-Triples) is a resource with multiple
serializations.  Each of those serialization technologies introduces
some inessential information (eg the whitespacing), which you're not
generally supposed to pay attention to.

If you want to identify RDF graphs in some pure way, keeping people safe
from the dangers of conflating the data-container with the data in that
container, then please don't something that looks like a URL.  Probably
it's best to use a secure hash of the RDF graph (using some technique
for graph hashing) for something like that, but you could use a
non-dereferenciable URI (eg a tag URI), I guess.

> Think about it, though. You don't want the TAG kicking down your door at 3am.

I know you're being metaphorical, but I don't find authoritarian imagery
helpful here.  The W3C operates by a form of consensus process (albeit
an imperfect form), which generally lets us steer clear door kicking :-)

There are plenty of legitimate nightmare scenarios, if you want to
invoke one, like saying that a proposal like this could have active
debate for many years and still be stuck, no where near consensus.

   -- Sandro
Received on Tuesday, 18 December 2007 13:54:42 GMT

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