THE BASIC PROCEDURES AND POPULATION PROJECTION USES OF INPUT-OUTPUT ANALYSIS, REGRESSION ANALYSIS, AND MARKOV CHAINS ARE NOTED. BASIC CONCEPTS IN COMPUTER SIMULATION, SUCH AS RANDOM VARIABLES, DISTRIBUTION FUNCTIONS, ETC., ARE EXPLAINED. FLOW DIAGRAMS ILLUSTRATE THE ANALYSIS OF CALIFORNIA CORRECTIONS SYSTEM ACTIVITY ON WHICH COMPUTER SIMULATIONS OF THAT ACTIVITY ARE BASED. CALIFORNIA'S USE OF COMPUTER SIMULATION TO TRACK INDIVIDUALS THROUGH THE SYSTEM AND TO DEVELOP, ON THE BASIS OF THE TRACKINGS, POPULATION PROJECTIONS FOR THE DEPARTMENT'S PAROLE AND INSTITUTIONAL PROGRAMS IS DESCRIBED. CHARTS SHOW TYPICAL INPUT DATA AND COMPUTER PRINTOUTS FOR SIMULATIONS AND A COMPARISON OF THE RESULTS OF FOUR SIMULATION RUNS GENERATING PROJECTIONS FOR CALIFORNIA'S INSTITUTIONALIZED MALE FELON POPULATION FROM 1977-1987. AN OUTLINE OF THE SYSTEM STATES (INSTITUTION, PAROLE, SUSPENDED PAROLE) POSTULATED BY THE DEPARTMENT'S INPUT/OUTPUT MODEL AND OF THE INPUT/OUTPUT VARIABLES FOR EACH STATE IS INCLUDED, TOGETHER WITH A LIST OF REFERENCES. (LKM)