The purpose of this study was to provide some basic facts about postdoctoral study in the United States. The report begins with a review of the history of postdoctoral education since its beginning more than 50 years ago. Succeeding chapters consider in detail the composition and distribution of the postdoctoral population; the significance of postdoctoral education for the individual, the department, and the institution of which he is temporarily a member; the character of postdoctoral education in different fields of study; the manner in which postdoctoral education is supported and provided for; and the costs of postdoctoral education. The report concludes with recommendations based on the findings, and appendices which include the questionnaires, compilations of data, and a bibliography. (AF)