THIS PAPER IS THE FIFTH OF SIX PRODUCTS OF A NATIONAL EVALUATION OF PRETRIAL RELEASE PROGRAMS TO DETERMINE THE CURRENT KNOWLEDGE OF THEIR EFFECTIVENESS, TO ASSESS THE USEFULNESS OF THIS KNOWLEDGE FOR PLANNING AND FUNDING DECISIONS, AND TO DEVELOP RESEARCH DESIGNS TO OBTAIN INFORMATION NECESSARY FOR A FULL EVALUATION. THE COMPARATIVE APPROACH AND EXPERIMENTAL RESEARCH DESIGNS ARE DISCUSSED. RESEARCH ISSUES CONSIDERED INCLUDE PROGRAM IMPACT ON RELEASE RATES AND THE COMPARATIVE EFFECTIVENESS OF ALTERNATIVE PROGRAM PROCEDURES. PROVISIONS FOR FOLLOW-UP STUDIES OF LEAA-FUNDED RESEARCH ARE ALSO REVIEWED. FOR THE OTHER FIVE PARTS OF THIS PHASE I EVALUATION, SEE NCJ-32738-40 AND NCJ-32742-43.