Improvement by Planned Multistage Selection

An outline of the problem of multistage selection is given, followed by examples of applications during the past 40 years. Optimal policies for successive selections among strains of crop plants are discussed. Animal breeding has analogous problems. The screening of chemical compounds for therapeutic uses has different features, notably in the formulation of a cost structure. The problems of selection from human populations are mentioned—those not selected now cannot be discarded. In this article I concentrate on the relation of the statistical formulation and analysis to the applications. Much has been done, and much remains to be done, in mathematical theory and computation.