The effects of a self-instructional package on three overactive preschool boys were investigated using a multiple-baseline design across subjects. Behavioral observations of the three target subjects indicated transfer of training effects from the experimental tasks to the classroom. On-task behaviors increased dramatically concomitant with the introduction of the self-instructional package, and treatment gains were maintained 22.5 weeks after baseline was initiated. In addition, the use of an observer-expectancy control condition gave further credibility to the demonstration of a causal relationship.DESCRIPTORS: self-instruction, on-task behavior, overactive behavior, verbal mediation, massed practice, transfer of training, preschool childrenThe widespread use of behavioral principles with children has led to the development of several effective procedures for decreasing disruptive behavior and increasing attention in school settings.