It is now close to 25 years since the appearance of the first edition and close to 50 years from the early developments in this field. In between there was a period of considerable activity that produced over 1,000 articles and about 6 books on the general theory of ranking and selection. In addition, the closely related topic of multiple comparisons is undergoing a recent revival of interest. Historically, the entire theory of ranking and selection is a direct outgrowth of the general decision theory as developed in the first half of this century, mostly by Abraham Wald and Abraham Girshick. Although they did not formulate the models used in ranking and selection procedures, it is hard to imagine how these procedures could have been developed without the pioneering work of Wald and Girshick.