ALAN KAZDIN'S empirical work and conceptual contributions have greatly enriched the study of child and adolescent dysfunction and treatment for many years. His research on the treatment of conduct disorder is a model of scientific elegance, and his thoughts on a research agenda for the field always warrant close attention. I certainly do agree with the author when he states that child and adolescent psychotherapy research should focus on understanding the mechanisms through which change takes place; that developmental psychopathology research and neuroscience findings should be used to inform treatment where possible; that judgments about treatment effects should be based on a broader range of outcomes than symptoms and diagnosis alone; and that a broad range of outcome-related questions should be addressed, including the identification of moderators that limit the range of treatment effects.