Evaluation of the Olweus Bully Prevention Program in an Urban School System in the USA.

This study evaluated the Olweus Bully Prevention Program (OBPP) in urban middle schools serving a mostly African American student population. Participants were 1791 students from three communities with high rates of crime and poverty. We evaluated the impact of the OBPP using a multiple-baseline experimental design in which we randomized the order and timing of intervention activities across three schools. We assessed the frequency of violence and victimization using self-report and teachers' ratings of students collected every 3 months over 5 years. Initiation of the OBPP was associated with reductions in teachers' ratings of students' frequency of aggression, with effects emerging in different years of implementation for different forms of aggression. Whereas reductions in teachers' ratings of students' verbal and relational aggression and victimization were evident during the second implementation year, reductions in physical aggression did not appear until the third year. Effects were consistent across gender and schools, with variability across grades for relational and verbal aggression and victimization. In contrast, there were no intervention effects on students' reports of their behavior. Positive outcomes for teachers', but not students' ratings, suggest the intervention's effects may have been limited to the school context. Variation in when effects emerged across outcomes suggests that changes in physical aggression may require more sustained intervention efforts. The intervention was also associated with increases in teachers' concerns about school safety problems, which may indicate that teachers were more attuned to recognizing problem behaviors following exposure to the OBPP.