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Re: RDF Concepts - What is a Node?

From: Dan Brickley <danbri@danbri.org>
Date: Tue, 29 May 2012 09:40:55 +0200
Message-Id: <C95E6BAA-2860-4E79-84AF-696DCA700229@danbri.org>
Cc: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, Richard Cyganiak <richard@cyganiak.de>, RDF WG <public-rdf-wg@w3.org>, David Wood <david@3roundstones.com>
To: "nathan@webr3.org" <nathan@webr3.org>




On 29 May 2012, at 09:30, Nathan <admin@webr3.org> wrote:

> Dan Brickley wrote:
>> On 29 May 2012, at 03:15, "Peter F. Patel-Schneider" <pfpschneider@gmail.com> wrote:
>>> On 05/28/2012 01:41 PM, Richard Cyganiak wrote:
>>>> Hi Nathan,
>>>> 
>>>> On 28 May 2012, at 17:02, Nathan wrote:
>>>>> Generally we see an RDF Graph as a Set of Statements, and the meaning of that is the conjunction of all the Statements in the Graph; and where each Graph entails its powerset.
>>>> Yes.
>>>> 
>>>>> However, it seems like there is an unwritten assumption in the community, that the meaning of a Node within a Graph is the conjunction of all the statements made where that node is in the subject or object position.
>>>> Nodes in an RDF graph don't have meaning.
>>> I beg to differ!
>> To avoid this kind of ping-pong and give a name to a useful concept, how about we name the rawest level? Plain triple / graph data structure, minimal additional assumptions. "RDF-Zero".
> 
> What do we call the thing which is the conjunction of the set of statements/assertions for a node within an RDF Graph then? the CBD?

I'm not sure it's a clear enough concept to name. Incoming and outgoing edges are equally relevant. Bnode vs Uri is quite arbitrary.

Fwiw the 1st (oct 97) spec called the outgoing edges collectively a 'description'. But many practical descriptions need several of these, and direction of property naming (eg depicts. Vs depiction) is arbitrary.

Dan


> It seems like a rather large concept which goes strangely undefined / unnamed in the RDF specs - and the original reason for the mail. I wrongly termed it the "node" in my original mail which led to some confusion, and if I'm getting confused / don't know what to call this concept which is pretty pivotal to RDF usage, then I'd suggest it may be useful to define / provide for others.
> 
> Best,
> 
> Nathan
Received on Tuesday, 29 May 2012 07:44:49 GMT

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