The two themes dealt with at the conference included European migration and crime, and the relationship between types of offenders and types of treatment. Using criminological data obtained from member States of the European Council, a preliminary discussion of the antisocial behavior of European migrants is presented. The report reviews the literature on the psychological adjustment of migrants, describes workers' migration to Europe and the criminality of European migrant workers, and recommends directions for future research. The second report explores the typology of offenders and typology of treatment, based primarily upon the work of French clinicians. Following an outline of the history of ideas and methods related to offender treatment, the authors offer a critical analysis of the ideas and research relating to the application of mathematics to medical and psychiatric clinical work and their adaptation to criminology. In the same vein, another report reviews the most important research to date in the field of relating types of treatment to types of offender; the author assesses the potential value of this kind of research in improving the effectiveness of correctional systems. The final report describes the principles used in Sweden to determine what type of treatment an offender will receive, provides a frame of reference for the issue of treatment-offender matching, and suggests ways of reformulating the problem in order to develop new lines of research. Chapter references