- From: Danny Ayers <Danny.Ayers@highpeak.ac.uk>
- Date: Mon, 13 Dec 1999 12:26:31 +0000
- To: Daniel LaLiberte <liberte@w3.org>
- CC: "www-rdf-interest@w3.org" <www-rdf-interest@w3.org>
Hi, You say '...what matters is what you *do* with assertions...' which seems a little to be avoiding my question. My point is that for the inference engine to use e.g. Bayesian reasoning, some facility for certainty must be included. I'm a little uncertain (:-)) of your notation, and could probably answer better if you could spell this out for me. I'll try though, on the assumption that you are meaning something along the lines of : A --p--> B could be A = Freddy's cat p = has colour B = Red B --q--> C B = Red q = type of colour C = Primary which could allow us to have A --p--> x --q--> C so I suppose --p-q--> could be equal to --p--> x --q--> which is clear given the above example, but I'm not clear enough to see whether this can be generalised. But I'm slipping off my topic, so for the sake of argument let's say the above is all fair enough, then as the assertions have no element of uncertainty, then whatever you do with the assertions is fixed to this same premise. If however you had the following A --p--> B (probability 0.9) B --q--> C (probability 0.9) you could derive a probability for A --p-q--> C, so you could say 'there is a 0.81 (or somesuch) probability that Freddy's cat is a primary colour. To keep with the 'assertions-only' approach I imagine this could be expressed as : [s1] - type -> rdf:Statement [s1] - subject -> [Freddy's Cat] [s1] - predicate -> [colour] [s1] - object - > [Red] [s2] - type -> rdf:Statement [s2] - subject -> [s1] [s2] - predicate -> [certainty] [s2] - object - > [0.9] but I was wondering whether this is adequate to cover all eventualities. Is a rdf:Statement(probabilistic) type needed? Is there a better way of expressing [s2]? Cheers, Danny.
Received on Monday, 13 December 1999 07:26:59 UTC