Large sums of money are often spent on setting up different systems of helping disruptive students without reference to objective data on effectiveness. This paper considers 24 alternative systems and scrutinizes the evaluation research on each. It finds that besides the most expensive systems not necessarily being the most effective, that the task of resolving behavioral difficulties may be either under- or over-resourced in individual cases, building in either failure or waste. A guide is given to developing a sequence of intervention strategies of known cost effectiveness, providing a fail-safe structure for helping disruptive adolescent students. Figures are included. (Author abstract modified)