THE STUDY CONSISTED OF 500 PERSONS SELECTED FROM ALL THOSE SENTENCED TO PROBATION WITHOUT ANY TYPE OF DETENTION BETWEEN JULY AND DECEMBER OF 1974; 405 WERE MALES AND 95 WERE FEMALES. DATA SHOWED THAT 59 PERCENT OF THE SUBJECTS REOFFENDED WITHIN 30 MONTHS OF THEIR PROBATION SENTENCE. PROBATIONERS AGES 20 YEARS OR LESS, WITH AN UNSKILLED JOB OR NO JOB AT ALL, AND WITH A PREVIOUS OFFENDING HISTORY WERE SIGNIFICANTLY MORE LIKELY TO REOFFEND. IF FIRST OFFENDERS DID REOFFEND, THE OFFENSE TENDED TO BE LESS SERIOUS THAN THEIR PROBATION OFFENSE; THE REOFFENSE OF THOSE WITH PREVIOUS CONVICTIONS WAS USUALLY MORE SERIOUIS THAN THEIR PROBATION OFFENSE AND MATCHED IF NOT EXCEEDED THE SERIOUSNESS OF ANY PREVIOUS OFFENSE. HOWEVER, MOST REOFFENDING WAS DONE WITHIN 6 MONTHS OF THE SENTENCE, AND THE RISK OF REOFFENDING TENDED TO DECREASE WITH TIME. THE APPENDIXES PROVIDE OFFENSE CLASSIFICATIONS AND VARIABLE DEFINITIONS USED IN THE ANALYSIS. TABULAR DATA AND REFERENCES ARE INCLUDED. (RCB)