Proposes model building as a pragmatic and integrative approach to developmental psychopathology. The model-building process is iterative within a program of research, cycling through the following phases of research: theory, field observation, construct definition, measurement development, construct analysis, model testing, experimental field trials, and model revision. Research on the development of and interventions for antisocial behavior is discussed as a tool for reflecting on the model-building process. The ecological framework is offered as a science-based heuristic that integrates various levels of analysis and theoretical perspectives.