Lecture notes from a RAND Social Science Department seminar, October 1979. To understand how psychologists talk about risk, what is meant by "risk" and by "psychological approach" are first defined. Following these definitions, an overview is provided of the general philosophy, technical orientation and methodology of the major schools of psychological approaches to risk. These approaches will all turn out to be variations of classical expected utility models. Finally, social psychological suggestions are made as to new conceptualizations of types of risk that are necessary for an intelligent study of social policy in uncertain environments.