Abstract
Research on school-based prevention suggests that the success of prevention programs depends on whether they are implemented as intended. In antibullying program evaluations, however, limited attention has been paid to implementation fidelity. The present study fills in this gap by examining the link between the implementation of the KiVa antibullying program and outcome. With a large sample of 7413 students (7-12 years) from 417 classrooms within 76 elementary schools, we tested whether the degree of implementation of the student lessons in the KiVa curriculum was related to the effectiveness of the program in reducing bullying problems in classrooms. Results of multilevel structural equation modeling revealed that after nine months of implementation, lesson adherence as well as lesson preparation time (but not duration of lessons) were associated with reductions in victimization at the classroom level. No statistically significant effects, however, were found for classroom-level bullying. The different outcomes for victimization and bullying as well as the importance of documenting program fidelity are discussed.
