This thesis analyses the ontological nature of quantum particles. In it I argue that quantum particles, despite their indistinguishability, are objects in much the same way as classical particles. This similarity provides an important point of continuity between classical and quantum physics. I consider two notions of indistinguishability, that of indiscernibility and permutation symmetry. I argue that neither sort of indistinguishability undermines the identity of quantum particles. I further argue that, when we understand in distinguishability in terms of permutation symmetry, (...) classical particles are just as indistinguishable as quantum particles; for classical physics also possesses permutation symmetry. (shrink)

In the present paper we face the problem of estimating cell probabilities in the case of a two-dimensional contingency table from a predictive point of view. The solution is given by a double stochastic process. The first subprocess, the unobservable one, is supposed to be exchangeable and invariant. For the second subprocess, the observable one, we suppose it is independent conditional on the first one.