Making a single decision

Chapter 9 provides an introduction to Part III by presenting ways to represent uncertainty in the process of making a single decision. The view taken in this chapter is that uncertainty can be modeled as interference from another decision maker. A special decision maker called nature will be introduced. The task is to make good decisions, in spite of actions applied by nature. Either worst-case or probabilistic models can be used to characterize nature's decision-making process. Some planning problems might involve multiple rational decision makers. This leads to game theory, which arises from the uncertainty about how other players will behave when they have conflicting goals. All of the concepts in Chapter 9 involve making a single decision; therefore, a state space is generally not necessary because there would only be one application of the state transition equation. One purpose of the chapter is to introduce and carefully evaluate the assumptions that are typically made in different forms of decision theory. This forms the basis of more complicated problems that follow, especially sequential decision making and control theory.