What Works for Whom? Evaluating Patterns and Mechanisms of Change Among Bullies, Victims, and Bully-Victims Participating in a School-Based Prevention Program

Abstract The effectiveness and program mechanisms of a whole-school anti-bullying that builds on the socio-ecological framework were investigated by applying person-oriented methods data analyses. A longitudinal cluster randomized control study was utilized comprising 1377 adolescents (48.5% girls, M age = 11.7) who participated in 1-year whole school implemented 13 schools 665 (45.2% 11.6) attended 5 schools. Student reports collected at pre- post-test within interval. Applying latent profile analyses (LPA), students actively involved bullying as perpetrators (e.g., bullies), target victims), both bully-victims), not either or victims uninvolved) identified. Latent transition (LTA) patterns between bully, victim, bully-victim, uninvolved subgroups intervention group before after implementation. Program higher probability compared to group) found for bully-victims. It explored whether changes differently related these sub-group memberships group. Victims transiting increased help-seeking norms, while bully-victims help-seeking, perceived teacher intervention, norms. can be concluded this works different sub-groups change drive students.