ANALYSIS OF SENTENCING PROBLEMS AND POSSIBLE SOLUTIONS INDICATES FOUR BASIC DIFFICULTIES: IRRATIONALITY; DISPARITY; INEFFECTIVENESS; AND DIFFUSION. ALTHOUGH THE PAROLE DECISION GUIDELINES SYSTEM ADDRESSES ONE ASPECT OF SENTENCING, EXPANSION OF THE GUIDELINES SYSTEM TO THE ENTIRE SENTENCING PROCESS REQUIRES A MESHING OF DIFFERENT PARTS OF THE CRIMINAL JUSTICE SYSTEM BY MEANS OF AN INSTITUTIONAL APPROACH. THE SENTENCING COMMISSION REPRESENTS SUCH AN APPROACH. A COMMISSION MODEL IS DISCUSSED IN TERMS OF FUNCTIONS AND POWERS WITHIN THE COMMISSION AND VIS-A-VIS PROSECUTORS, JUDGES, AND PAROLE BOARDS. THE COMMISSION, WHICH WOULD PERFORM EVALUATION, PLANNING, AND POLICYMAKING FUNCTIONS, WOULD BE SUPPORTED BY AN ADVISORY GROUP AND A PROFESSIONAL STAFF AND WOULD BE COMPOSED OF PROSECUTORS, JUDGES, AND PAROLE BOARD REPRESENTATIVES. THE PROPOSED MODEL IS DISCUSSED IN THE GENERAL CONTEXT OF AN AMERICAN STATE; PECULIARITIES OF LOCAL LAWS AND INSTITUTIONS ARE NOT CONSIDERED. THE MODEL IS SET INTO A THEORETICAL BASE, AND EARLIER PROPOSALS FOR COMMISSION MODELS ARE EXAMINED. SPECIAL PROBLEMS THAT A SENTENCING COMMISSION IS LIKELY TO ENCOUNTER -- LINKAGE WITH THE STATE PLANNING AGENCY, RESISTANCE TO CHANGE -- ARE CONSIDERED. THE PROVISIONS OF A SENATE BILL PROPOSING A FEDERAL SENTENCING COMMISSION ARE EXAMINED IN LIGHT OF THE MODEL. (AUTHOR ABSTRACT MODIFIED-LKM)