A HEURISTIC MODEL IS AN INFORMATION-PROCESSING MODEL DESCRIBED IN RULES OF THUMB, WHICH DEFINE THE OPERATION OF THE MODEL AND DYNAMICS OF THE SITUATION. THE PRIMARY CHARACTERISTICS OF THE MODEL INCLUDE A DEDUCTIVE INFERENCE CAPABILITY, DYNAMIC GROWTH AND REVISION OF DATA AND RULES WHICH CONSTITUTE JUDGMENTS, AND AN INTEGRATED COLLECTION OF KNOWLEDGE. REPRESENTATION OF INFORMATION IN PRODUCTION SYSTEM FORM IS ILLUSTRATED AND DISCUSSED. THE FIRST STEP IN BUILDING A HEURISTIC MODEL REQUIRES FORMALIZATION OF THE DOMAIN THROUGH THE EXTRACTION OF DATA AND RULES FROM EXPERTS ON TERRORISM. THROUGH DIALOGUES WITH EXPERTS AND PROTOCOL ANALYSIS, THREE FOCAL POINTS OF THE SYSTEM WERE IDENTIFIED: EVENT -- BOMBING, HIJACKING, KIDNAPING, ETC.; CONTEXT -- POLITICAL/ECONOMIC ENVIRONMENT, INTERNAL SECURITY, ETC.; AND GROUP -- SIZE, IDEOLOGY, AND OTHER ATTRIBUTES. VALUES FOR THE ATTRIBUTES WERE THEN FORMULATED. RULES FOR THE RELATIONSHIPS AMONG VARIABLES WERE THEN DERIVED BY HAVING TERRORISM EXPERTS EXAMINE EACH STEP OF THEIR DECISIONMAKING PROCESSES IN ARRIVING AT JUDGMENTS ABOUT PARTICULAR ASPECTS OF EVENTS, CONTEXTS, AND GROUPS AND THEIR ATTRIBUTES. WHEN OPERATIONAL, THE HEURISTIC MODEL WILL PROVIDE SOCIAL RESEARCHERS WITH A TOOL, IN THE FORM OF COMPUTER PROGRAMS, THAT WILL AID IN THE ANALYSIS OF TERRORIST ACTIVITIES AND SHOULD PROVE PARTICULARLY USEFUL IN CRISIS SITUATIONS WHEN TIME FACTORS ARE CRITICAL. THE SYSTEM ENVISIONED WOULD PROVIDE A STRAIGHTFORWARD WAY OF PROCEEDING TOWARD A SOLUTION, BY ASKING QUESTIONS ABOUT AN EPISODE AND PRODUCING DEMANDS FOR THE MOST RELEVANT DECISIONMAKING INFORMATION. IT WOULD ALSO PRODUCE FROM ITS OWN MEMORY RELEVANT JUDGMENTS MADE ABOUT SIMILAR EVENTS, GROUPS, OR CONTEXTS IN THE PAST, THUS ADDING TO THE OVERALL EXPERT OPINION AVAILABLE. APPENDIXES INCLUDE DOMAIN FORMALIZATION FOR TERRORIST BOMBING, EXPERT JUDGMENT ANALYSIS PROTOCOL, AND REFERENCES. (JAP)