An introductory chapter reviews the scope and purposes of correctional treatment and deals with the philosophical frameworks for punishment and treatment models in corrections. Three articles highlight the debate over the effectiveness of correctional treatment; the 'Nothing Works' doctrine and the research results written up in 'The Effectiveness of Correctional Treatment,' a book which was based on a survey of 231 studies covering the years 1945-67, are discussed in particular. Additional chapters describe the characteristics, job attitudes, and unique problems of those involved in correctional work and describe a study which developed a profile of the volunteer correctional staff. The many facets of a case, such as offender age, sex, family history, and offense record, that may affect the type of treatment chosen are reviewed. Various classification systems developed, implemented, and evaluated by experts in the field are described; these include the uniform, cross-classification, Quay, and I-level systems. The first two are based on demographic and offense variables and the last two use intelligence and personality scores as bases. Next the National Advisory Commission on Criminal Justice Standards and Goals' recommendations on classification of offenders are given. In addition, detailed descriptions of various correctional treatment techniques cover crisis intervention and counseling, reality therapy, behavior modification, and several forms of group treatment. A final chapter summarizes the success and problems of correctional treatment and available evaluation data, and it explores the possible effects of current trends on the future of correctional treatment. Notes are provided for each chapter. References, tabular data, and a bibliography of about 175 citations are included. (Author abstract modified)