AN OUTSIDER OBSERVING THE CRIMINAL JUSTICE SYSTEM IS STRUCK BY THE CONTRAST BETWEEN THE CAREFUL REGULATION IMPOSED ON THE TRIAL PROCESS AND THE ARBITRARINESS OF SENTENCING DECISIONS. PROPOSALS FOR SENTENCING REFORM ARE AFOOT AND CAN BE CLASSIFIED AS (1) THE MANDATORY MINIMUM SENTENCE LEGISLATIVELY MANDATED FOR SERIOUS OFFENSES, (2) PRESUMPTIVE SENTENCES WHICH PERMIT THE JUDGE TO INVOKE MITIGATING CIRCUMSTANCES TO JUSTIFY ALTERNATIVES TO IMPRISONMENT, AND (3) GUIDELINES DEVELOPED BY A SENTENCING COMMISSION. RESEARCH ON CURRENT SENTENCING PRACTICES OF JUDGES IN PENNSYLVANIA INDICATED THAT JUDGES DO SENTENCE ACCORDING TO THE MANDATORY MINIMUM CONCEPT, ESPECIALLY WHEN DECIDING ON SERIOUS OFFENSES AND OFFENSES OUTSIDE LARGE URBAN CENTERS. LEGISLATIVELY MANDATED SENTENCES WILL RESULT IN A NEED FOR CURRENTLY UNAVAILABLE RESOURCES IN THE CORRECTIONS SYSTEM; CONSEQUENTLY, A SENTENCING COMMISSION TO REVIEW CURRENT PRACTICES AND PROPOSE GUIDELINES WOULD BE MORE FEASIBLE. A NATIONAL ACADEMY OF SCIENCES REPORT SHOWS THAT RESEARCH ON DETERRENCE IS INCONCLUSIVE BUT STATES THAT A MAJOR REDUCTION IN CRIME THROUGH INCREASED USE OF INCARCERATION WOULD REQUIRE A SIGNIFICANT INCREASE IN THE PRISON POPULATION.