THE BASE EXPECTANCY PROGRAM CLASSIFIES INDIVIDUALS INTO GROUPS ESTIMATING THE DEGREE TO WHICH THEY ARE AT RISK OF CONTINUING THEIR CRIMINAL CAREERS AFTER RELEASE INTO THE COMMUNITY. ONCE CONSTRUCTED, IT CAN BE USED AS A MEANS OF COMPARISON FOR INDIVIDUALS WHO HAVE PARTICIPATED IN A PARTICULAR TREATMENT PROGRAM. IF A BASE EXPECTANCY TABLE IS USED AS A CONTROL IN A PARTICULAR STUDY, IT CAN ALSO CONTROL FOR THE POSSIBLITY OF A NONRANDOM SELECTION PROCESS. THE TABLE IS EXPLAINED IN THE REPORT, USING A SAMPLE OF 1975 RELEASEES FROM MASSACHUSETTS CORRECTIONAL INSTITUTIONS AS A DATA BASE. TWO TABLES WERE PRODUCED AS A RESULT: ONE BASED ON INFORMATION KNOWN WHEN AN INDIVIDUAL IS RELEASED (POSTINCARCERATION TABLE) AND ONE INCLUDING INFORMATION KNOWN WHEN AN INDIVIDUAL IS FIRST COMMITTED TO PRISON (PREINCARCERATION TABLE). WHEN THESE TABLES WERE APPLIED TO THE 1976 RELEASEE POPULATION, BOTH TABLES WERE VALIDATED. A GENERAL DESCRIPTION OF BASE EXPECTANCY PREDICTION DEVICES IS GIVEN, AND THE REPORT STATES THAT THE TABLES WILL BE USED AS CONTROLS IN FUTURE RESEARCH DONE BY THE MASSACHUSETTS DEPARTMENT OF CORRECTION. THE BULK OF THE REPORT CONSISTS OF TABULAR DATA. (AUTHOR ABSTRACT MODIFIED--MJW)