In this paper we formulate a particular statistical model validation p
roblem in which we wish to determine the probability that a certain hy
pothesized parametric uncertainty model is consistent with a given inp
ut-output data record. Using a Bayesian approach and ideas from the fi
eld of hypothesis testing, we show that in many cases of interest this
problem reduces to computing relative weighted volumes of convex sets
in R(N) (where N is the number of uncertain parameters). We also pres
ent and discuss a randomized algorithm based on gas kinetics, as well
as the existing Hit-and-Run family of algorithms, for probable approxi
mate computation of these volumes.