Introduction

Abstract

Many multi-stage decision systems are known to be in one particular state at a given point in time and then to change irrevocably into another state. The decision maker (DM), who cannot observe the true state directly, gathers and processes information over time in an attempt to detect the time of change, balancing between the cost of information acquisition and the cost associated with making an incorrect decision. In this book we formulate several classes of detection of change tasks and develop several response models for describing the DM’s behavior. To do so, mathematical notation and formalism are necessary. Didactically, however, it seems preferable to start our presentation with a few examples. Thus, without undue formalism, three examples are briefly described below both to motivate the entire enterprise and to illustrate the scope and some of the major features of the decision situations examined.