- From: Seth Russell <seth@robustai.net>
- Date: Tue, 14 Jan 2003 11:31:19 -0800
- To: Bob MacGregor <macgregor@ISI.EDU>
- CC: Dave Reynolds <der@hplb.hpl.hp.com>, www-rdf-interest@w3.org, tar@ISI.EDU, hans@ISI.EDU
Bob MacGregor wrote: > If we were using a quad representation, then memory is linear in > the number of quads. However, wrt quads, I'm not sure our notion is > in sych with the statings crowd. Suppose the quad form is > > [C1 S P O] > [C2 S P O] > [C3 S P O] > > While we conceptualize this as one triple [S P O], asserted > in three different contexts, the statings crowd seems two think of > these quads as three different statings that are only loosely > related. I missed it, what is not in sync with the stating crowd (you count me in that context) ? > What the semantics of the above is can't really be resolved unless we > decide on what a quad is (for example, must one of its arguments always > be a context?) and what a context is (e.g., is a context a set of > assertions or a set of statings?). I think we need two concepts here: Model, and Context. A model (sometimes called a graph) is just a collection of triples - nothing more, nothing less. To be completely general I wouldn't even attach any notion of Truth to the collection - often we collect triples without regard to whether they are true or not. A Context is a Model, but a Context may contain other properties, amoung which might be: 1) the agent or agents who collected the triples and 2) some other object (resource, purpose, catagory, whatever ...) that the context is about. To summarize and answer your specific questions according to my conception: 1) The fourth URI or blank node identifier of a Quad must always identify a Model. 2) A model is a set (collection?) of statings. 3) A Context is a Model that has been further adapted to serve the needs of a specific group of agents or applications or purposes or catagories. Check out <http://topicexchange.com/> , is that application starting to establish Contexts ? Seth Russell
Received on Tuesday, 14 January 2003 14:31:53 UTC