ABSTRACT
The proof of the pudding being in its eating, we shall in this final chapter apply the observation selection theory to the fine-tuning and freak-observer problems in cosmology, to the Sleeping Beauty problem in game theoretic modeling of imperfect recall, and to the other scientific issues that we have studied (in evolution theory, thermodynamics, traffic analysis, and quantum physics). Then, towards the end, we shall argue that one can say something about how scientifically rigorous a given application is by looking at what sort of demand it places on how the reference class be defined. In general, weaker demands correspond to greater scientific rigor. Paradoxical applications are distinguished from the more scientific ones by the fact that the former work only for a rather special set of reference classes (which one may well reject) whereas the latter hold for a much wider range of reference classes (which arguably any reasonable person is required not to transgress). We will also tie this in with the foregoing discussion of the element of subjectivity that may exist in the choice of reference class.
