1. A method suitable for deciding how to classify a sample in one of a number of predetermined classes, the method comprising: (a) associating a weight w ij with each of a plurality of classifiers i which are class models for how to classify a sample j in one of a number of predetermined classes k; (b) calculating for each of said predetermined classes k a weighted summation CL jk across said classifiers i of the likelihood l ijk that the sample belongs to that respective class k, weighted by the weight w ij ; and (c) designating the sample j as belonging to the class k which has an associated weighted summation of likelihoods CL jk which is greatest in value.