The criminological and penological literature contains two principal conceptions of The older conception considers as those general systems and general programs used for handling criminals and assumed to be somehow reformative. Thus, imposition of either physical or psychological pain, in any of a variety of settings, continues to be viewed as a general system for correcting criminals. Similarly, one rationale for introducing and maintaining general programs such as probation, parole, and imprisonment has been that these programs are or will be more correctional than the programs used in the past. A newer conception of however, places more emphasis on the specific methods used in attempts to change individual criminals. While descriptions of such methods are by no means as precise as descriptions of medical techniques, an analogy with clinical medicine is made, with the result that utilizing the methods is called or therapy. Thus, within a parole or probation organization, the agents may help offenders find jobs, order them to stay out of saloons, or counsel them on psychological problems of adjustment. Because each of these maneuvers is assumed to have some efficacy in changing criminals into noncriminals, each is viewed as a treatment or technique. Similarly, prisoners may be enrolled in prison schools, ordered to work, given vocational counseling and training, or engaged in individual or group psychotherapeutic interviews. These specific programs also are viewed as techniques. This paper will be devoted to closer identification of these two conceptions of techniques, to discussion of the problems involved in measuring the effectiveness of defined in either the first or the second sense, and to exploration of possible reasons for reluctance to define techniques more precisely. *B.S. 1943, Iowa State College; Ph.D. I950, Indiana University. Chairman, Department of Anthropology and Sociology, University of California, Los Angeles; Research Consultant, California Department of Corrections; Research Advisory Board, California Board of Corrections. Sociologist, Illinois State Penitentiary, I949; Research Associate, United States Penitentiary, Terre Haute, Indiana, 1951; Research Associate, California Institution for Men, 1950-5I; Research in the Wisconsin State Prison and the Wisconsin State Reformatory, I955-56, while attached to the Center for Education and Research in Corrections, University of Chicago. Author, OTHER PEOPLE'S MONEY (1953); co-author [with Edwin H. Sutherland], PRINCIPLES OF CRIMINOLOGY (5th ed. 1955). Contributor to sociological, legal, and publications.