IN MICHIGAN, PUBLIC PROTECTION IS VIEWED AS THE OVERALL AIM OF ANY CRIMINAL PENALTY. RETRIBUTION, DETERRENCE, REHABILITATION, AND ISOLATION ARE THE ASPECTS OF PENALTY RELATED TO CRIME PREVENTION AND PUBLIC SAFETY. OTHER ASPECTS INCLUDE JUSTICE AND COST-EFFECTIVENESS. MICHIGAN'S MODIFIED INDETERMINATE SENTENCING STRUCTURE AND PAROLE SYSTEM HAVE BEEN CRITICIZED FOR THE DISPARITIES AND FAILURES OF JUSTICE THAT SOMETIMES OCCUR. ALTERNATIVE SENTENCING STRUCTURES INCLUDE DETERMINATE OR FLAT SENTENCING, MANDATORY PRISON TERMS, AND PRESUMPTIVE SENTENCING. THE BASIC ADVANTAGES OF THE EXISTING INDETERMINATE SENTENCING/PAROLE STRUCTURE ARE POINTED OUT. A MAJOR ADVANTAGE IS THAT THE CORRECTIONAL SYSTEM HAS THE OPPORTUNITY TO REACT TO CHANGES IN INDIVIDUAL OFFENDERS. THE NEED FOR REVISIONS IN THE EXISTING STRUCTURE TO PROTECT AGAINST ABUSES IS NOTED. IT IS RECOMMENDED THAT PROPOSALS TO REVISE SENTENCING POLICIES BE JUDGED BY THE FOLLOWING CRITERIA: (1) INCLUSION OF ADEQUATE PENALTIES FOR VERY SERIOUS CRIMES; (2) PROVISION OF A REASONABLE RANGE OF DISCRETION FOR JUDGES; (3) PROVISION FOR THE CORRECTIONS SYSTEM TO ACT IN LIGHT OF WHAT IT LEARNS ABOUT AN OFFENDER; (4) LIMITATION AND CONTROL OF THE CORRECTIONS SYSTEM'S DISCRETION; AND (5) CONSIDERATION OF THE OFFENDER'S CONDUCT AS A FACTOR IN PAROLE DECISIONS.