This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the…

Visual inspection of data is a common method for understanding, responding to, and communicating important behavior-environment relations in single-subject research. In a field that was once dominated by cumulative, moment-to-moment records of behavior, a number of graphic forms currently exist that aggregate data into larger units. In this…

Several Federal programs and initiatives are underway to reduce crime and violence in the schools. In connection with these efforts, Congress had passed legislation requiring the National Center for Education Statistics to collect data about the seriousness and incidence of violence in elementary and secondary schools. This report presents an…