 In classical probability theory (and especially in classical statistics) one usually focuses, not on the set of all possible probability weights, but on some designated subset of these (e.g., those belonging to a given family of distributions). Accordingly, by a probabilistic model, I mean pair \((\mathcal{A},\Delta)\) consisting of a test space \(\mathcal{A}\) and a designated set of states \(\Delta \subseteq \Omega(\mathcal{A})\) on \(\mathcal{A}\). I’ll refer to \(\mathcal{A}\) as the test space and to \(\Delta\) as the state space of the model.