Numeric databases can support the application of quantitative methods to the study of terrorism. Methods are outlined that can ultimately provide a system for monitoring and projecting aggregate trends in subnational violence. Such methods can also extract information for basic research and analysis of policy. The proposed approach to research is divided into two phases. First, methods are developed to create a set of profiles defining the behavior patterns of individual terrorist groups. The profiles are a set of numeric indexes, each of which measures the frequency, severity, quality, and effect of terrorist acts. Aggregate profiles would be created to reflect national, regional, and international behavior. Second, the profiles of the attributes of terrorism would be used as the empirical base for more sophisticated modeling.