Effectiveness of programs to prevent school bullying

Sixteen major evaluations of programs to prevent school bullying, conducted in 11 different countries, are reviewed in detail. Of these 16 evaluations, 8 produced desirable results, 2 produced mixed results, 4 produced small or negligible effects, and 2 produced undesirable results. These varying findings may reflect variations in programs, in implementation, in assessment methods, or in evaluation designs. It is concluded that high-quality evaluations are needed in the future, with randomized designs, theoretically grounded interventions, multiple measures of bullying, and attempts to disentangle the effectiveness of different program components.