I've been lurking & reading the discussion with interest.
It might be worth pointing out that there is an ongoing attempt to classify/ represent evidential links/ weight/ etc. started in the legal domain by people such as Wigmore and continued by people such as David Schum & William Twining. There's currently a Leverhulme-sponsored research programme on "Evidence Science", centered at UCL, London.
Such efforts don't seem to easily map to rdf (they're often based on Bayesian models), but might provide some inspiration, although some of the legal niceties may be unnecessary.
I also know that the issue has been looked at by some in the argumentation community, where the "source" of the rules that make the argument need to be defined.
If anyone is interested in these, please contact me off-list. Thanks, Matt -- http://acl.icnet.uk/~mw http://adhominem.blogsome.com/ +44 (0)7834 899570
