18. The apparatus of claim 12 wherein said Bayesian inference processor computes said precision probability distribution using a beta binomial model stored in a non-transitory machine readable medium.
19. The apparatus of claim 18 wherein said beta binomial model has a root node and a plurality of leaf nodes, wherein the precision probability distribution is represented by one of said plural leaf nodes and wherein the root node represents an overall grouping precision distribution of the collective plural leaf nodes.