THIS PAPER IS BASED ON WORK SUPPORTED BY THE UNITED STATES BUREAU OF PRISONS UNDER A CONTRACT WIH THE UNIVERSITY OF NORTH CAROLINA. THE EXPERIMENTS UNDER STUDY REFLECT THE SHIFT IN CORRECTIONAL PHILOSOPHY FROM TRADITIONAL PENOLOGICAL CONCEPTS TO AN IMPRISONMENT MODEL IN WHICH VARIOUS PROGRAMS COULD BE SIMULTANEOUSLY TRIED AND EVALUATED FOR INMATE PARTICIPATION AND RESULTS. PRISONERS WERE ABLE TO CHOOSE THE PROGRAMS IN WHICH THEY WISHED TO PARTICIPATE, NONE OF WHICH WERE MANDATORY. FAILURE TO ENROLL IN ANY OF THE PROGRAMS OFFERED HAD NO BEARING ON INMATES' RELEASE DATES OR THE CONDITIONS OF IMPRISOMENT. PARTICIPANTS IN THESE VOLUNTARY PROGRAMS WERE SURVEYED TO DETERMINE THEIR PERCEPTIONS OF THE PROGRAM'S EFFECTIVENESS AND ATTRACTIVENESS, AND FOR RESULTS ON THE INMATES' BEHAVIOR AFTER RELEASE. CONTROL GROUPS IN TRADITIONALLY-RUN CORRECTIONS WERE ALSO CHOSEN TO DETERMINE THE SAME BEHAVIORAL VARIABLES. THREE YEARS OF TESTING SHOWED A HIGH RATE OF INMATE ENROLLMENT IN THE PROGRAMS OFFERED AT THE MODEL PRISON (A FEDERAL CORRECTIONAL INSTITUTION), AND A LOW RATE OF WITHDRAWAL. EXPRESSIONS OF INMATES' SATISFACTION WITH THE ACTIVITIES WERE ALSO AMONG THE POSITIVE FINDINGS. SELF-IMPROVEMENT, PROGRAM USEFULNESS, AND WORKING CONDITIONS WERE CITED AS REASONS FOR POPULARITY OF THE PROGRAM. COMPARATIVE FINDINGS OF POST-RELEASE BEHAVIOR OF TARGET POPULATIONS VERSUS CONTROLS ARE NOT AVAILABLE YET. EVEN THOUGH THE VOLUNTARY NATURE OF PROGRAM PARTICIPATION AND ITS IRRELEVANCE TO INMATES' FIXED RELEASE DATES OR PRISON CONDITIONS WAS CLEARLY STATED AT THE START, INMATES CONTINUED TO PERCEIVE A NON-EXISTENT TIE BETWEEN PROGRAM PARTICIPATION AND INSTITUTIONAL REWARDS. AN 11-ITEM BIBLIOGRAPHY IS PROVIDED.