Statistical methods provide the mathematical and conceptual means to evaluate statistical hypotheses in the light of a sample. To this end the methods employ probability theory, and incidentally generalizations thereof. The evaluations may determine how believable a hypothesis is, whether we may rely on the hypothesis in our decisions, how strong the support is that the sample gives to the hypothesis, and so on. Good introductions to statistics abound (e.g., Barnett 1999, Mood and Graybill 1974, Press 2002).