WHEN A DEFENDANT APPEARS FOR SENTENCING, JUDGES HAVE VARIOUS SOURCES OF INFORMATION AVAILABLE: EVIDENCE ABOUT THE CRIME AND THE DEFENDANT THAT HAS BEEN PRESENTED AT TRIAL; JUDGES' OBSERVATIONS OF THE DEFENDANT IN THE COURTROOM; INFORMATION OFFERED BY THE PROSECUTION OR DEFENSE COUNSEL; PROBATION OFFICERS' PRESENTENCE INVESTIGATION REPORTS; AND SPECIAL REPORTS, INCLUDING THOSE RESULTING FROM PRESENTENCE STUDY COMMITMENTS. THE PRESENTENCE STUDY PROCEDURE ENVISIONS THE COURT ORDERING A PRESENTENCE STUDY COMMITMENT AND SPECIFYING WHAT INFORMATION THE COURT BELIEVES WOULD BE OBTAINABLE AND USEFUL IN SENTENCING. THE USUAL REASON FOR ORDERING SUCH A STUDY IS THE DESIRE FOR PSYCHOLOGICAL OR PSYCHIATRIC EVALUATION. ONLY A VERY FEW STUDIES ARE ORDERED FOR INFORMATION ON VOCATIONAL OR MEDICAL ASPECTS OF AN OFFENDER'S SITUATION OR FOR A RECOMMENDATION AS TO WHETHER AN OFFENDER IS A FIT SUBJECT FOR PROBATION. THE PRESENTENCE COMMITMENT IS OFTEN ORDERED WITH THE UNDERSTANDING THAT A COMPLETE STUDY WILL BE UNDERTAKEN. PRESENTENCE REPORTS OF PROBATION OFFICERS ARE USED AS THE FACTUAL BASIS FOR INSTITUTIONAL EVALUATION. A 60-DAY OR 90-DAY PERIOD IS SET DURING WHICH INTERVIEWS OR TESTS ARE SCHEDULED AND REPORTS ARE PREPARED AND REVIEWED. FINALLY, THE CHECKLIST FOR DEFENSE COUNSEL OUTLINES INFORMATION ON USING OR AVIOIDING PRESENTENCE STUDIES TO THE ADVANTAGE OF CLIENTS. FOOTNOTES ARE PROVIDED. (DEP)