The contextual measurement model (CMM) that was invented in Chapter 10 representsthe wide range of non-Bayesian procedures for probability updatebased on context updates (or state updates). In this chapter we compareBayesian classical probability inference with general contextual probabilityinference. CMM is the basis of the Växjö interpretation of quantum mechanics,one of the contextual probabilistic interpretations. This interpretationhighlights that quantum update of probability (based on the state update)is one of the non-Bayesian updates. Quantum mechanics is interpreted as aprobability update machinery.