THE INFORMATION TAKEN FROM THE OFFENDERS' RECORDS WAS SYSTEMATICALLY ENTERED ON A FORM ACCORDING TO A SCHEDULE OF CATEGORIES WITH APPROPRIATE SUBCLASSES OF FACTORS: (1) THE CIRCUMSTANCES AND CONDITIONS OF THE TRIAL AND COMMITMENT, (2) THE CIRCUMSTANCES AND CONDITIONS OF THE SOCIAL BACKGROUND, (3) THE TRAITS, HABITS, AND CHARACTERISTICS OF THE INDIVIDUAL, (4) THE PERIOD OF STAY IN THE INSTITUTION, AND (5) THE PERIOD ON PAROLE. OUTCOME ON PAROLE WAS CLASSED UNDER THREE HEADINGS--NONVIOLATORS, MAJOR VIOLATORS, AND MINOR VIOLATORS. THE PROPORTION OF MEN IN EACH SUBCLASS FOR EACH CATEGORY WHO WERE VIOLATORS WAS THEN COMPUTED, GIVING A PERCENTAGE VIOLATION RATE. SUCH RATES WERE COMPUTED SEPARATELY FOR THE TWO INSTITUTIONS AND FOR THE COMBINED GROUP OF PRISON AND REFORMATORY PAROLEES. TO SECURE A SINGLE CONSISTENT MEASURE OF THE RELATION BETWEEN EACH FACTOR OR CATEGORY OF INFORMATION AND OUTCOME ON PAROLE, CONTINGENCY COEFFICIENTS WERE COMPUTED FOR ALL THE CATEGORIES. BY PLACING THESE IN RANK ORDER SOME MEASURE OF THE RELATIVE IMPORTANCE OF EACH FACTOR WAS OBTAINED. HOWEVER, IT IS CLEAR THAT ONLY THOSE FACTORS HAVING TO DO WITH THE INMATE'S LIFE BEFORE PAROLE COULD BE IN CONSTRUCTING PREDICTION TABLES FOR PAROLE OUTCOME. THREE SERIES OF PAROLE PREDICTION TABLES WERE CONSTRUCTED ON THE BASIS OF THE 17 HIGHEST FACTORS IN THE CONTINGENCY LIST. THE 17 LOWEST, AND A SELECTED GROUP OF 25 PREPAROLE FACTORS, ALL WITH DATA AVAILABLE IN ALMOST ALL THE CASES. IT IS APPARENT THAT NO SIMPLE FACTOR OR SMALL GROUP OF FACTORS HAD ANY APPARENT RELATION TO PAROLE OUTCOME. HOWEVER, WHEN THE TOTAL RESULTS WERE COMBINED INTO CUMULATIVE TABLES, SIGNIFICANT DIFFERENCES APPEARED BETWEEN VIOLATORS AND NONVIOLATORS IN EVERY CASE. TABULAR DATA ARE INCLUDED. REFERENCES AND ADDITIONAL DATA ARE APPENDED. (KBL)