 Finally, one must define infinitesimal transition probabilities that will give rise to the proper quantum-mechanical probabilities at each time. Following earlier papers by Bell (1984), Vink (1993), and others, Bacciagaluppi and Dickson (1999) define an infinite class of such infinitesimal transition probabilities, such that all of them generate the correct single-time probabilities, which arguably are all we can really test. However, Sudbery (2002) has contended that the form of the transition probabilities would be relevant to the precise form of spontaneous decay or the “Dehmelt quantum jumps”; he independently develops the dynamics of Bacciagaluppi and Dickson and applies it in such a way that it leads to the correct predictions for these experiments. Gambetta and Wiseman (2003, 2004) have developed a dynamical modal account in the form of a non-Markovian process with noise, also extending their approach to positive operator-valued measures (POVMs). More recently, Hollowood (2013a, 2013b, 2014) has elaborated the idea that the dynamics of value states can be modeled by a discrete-time Markov chain.