A RANDOM SAMPLE OF 145 CASES OF INCEST AND 123 CASES OF CHILD MOLESTATION ARRAIGNED BEFORE THE SUPERIOR COURTS OF LOS ANGELES COUNTY (CALIF.) BETWEEN 1956 AND 1966 WERE EXAMINED, USING DATA DERIVED FROM PSYCHIATRIC REPORTS, PRESENTENCING EVALUATIONS, SENTENCING TRANSCRIPTS, AND OTHER MATERIALS CONTAINED IN THE OFFICIAL CRIMINAL RECORDS OF THESE CASES. DATA ANALYSIS WAS PERFORMED USING THE AUTOMATIC INTERACTION DETECTION PROGRAM; THE PROGRAM'S PROCESS IS ANALOGOUS TO A STEPWISE APPLICATION OF ONE-WAY ANALYSIS OF VARIANCE, WITH THE ORIGINAL SAMPLE PARTITIONED INTO A 'TREE' OF SUCCESSIVE NONOVERLAPPING SUBGROUPS TO YIELD THE GREATEST REDUCTION IN ERROR IN THE DEPENDENT VARIABLE. USING 18 PREDICTOR VARIABLES, MODELS WERE DEVELOPED TO PREDICT THE DECISION TO GRANT PROBATION, THE PROBATION OFFICER'S RECOMMENDATION, AND THE OFFENDER'S REACTION TO THE CHARGES. THE DATA INDICATED THAT PROBATION OFFICER RECOMMENDATIONS FOR PROBATION WERE FOLLOWED BY THE COURT OVER 95 PERCENT OF THE TIME, WHILE PROBATION OFFICER RECOMMENDATIONS AGAINST PROBATION WERE ACCEPTED AN AVERAGE OF 80 PERCENT OF THE TIME. WHILE PSYCHIATRIC EVALUATION, TYPE OF DEFENSE COUNSEL, AND THE AGE OF THE DEFENDANT ALSO FIGURED INTO THE DECISION TO GRANT PROBATION, THESE FACTORS WERE INVOLVED IN A RELATIVELY SMALL NUMBER OF CASES. PERSONAL OR DEMOGRAPHIC CHARACTERISTICS OF THE OFFENDER DID NOT PLAY A PROMINENT ROLE IN INFLUENCING PROBATION OFFICER RECOMMENDATIONS. INSTEAD, PROBATION OFFICERS RESEMBLE THE COURT IN THEIR INCLINATION TO FOLLOW THE ADVICE OF QUALIFIED PROFESSIONALS. THE OFFENDER'S CHANCES OF BEING RECOMMENDED FOR PROBATION ARE ALSO IMPROVED IF FORCE HAS NOT BEEN USED AND HE IS NOT ALLEGED TO HAVE MADE THE VICTIM PREGNANT. OFFENDERS WHO ADMIT AT LEAST SOME INVOLVEMENT IN THE OFFENSE WITH WHICH THEY ARE CHARGED, WITH ATTENDANT REMORSE, STAND A GREATER CHANCE OF A PROBATION RECOMMENDATION. THE MORE SERIOUS THE OFFENSE, THE MORE OFTEN DID THE OFFENDER DENY INVOLVEMENT, PRESUMABLY TO WARD OFF THE THREAT TO HIS IDENTITY OF A SERIOUS DEPARTURE FROM NORMATIVE BEHAVIOR. SUMMARY DATA ARE PROVIDED IN GRAPHIC FORM. REFERENCES ARE PROVIDED. (RCB)