At a time when psychological, educational, and health care programs are undergoing major restructuring, this new work presents a novel analysis of prevailing activity and new directions in intervention. Four fundamental topics of successful intervention are identified and described: classification, underlying rationales, planning and implementation, and evaluation. A useful feature is the variety of figures and tables that provide conceptual outlines of major facets of intervention activity, updating promising directions and advances. This work will be a valuable tool for both instructors and practitioners interested in a comprehensive, integrated approach to intervention.