skip to content

Violence Research Centre



Dr Hannah Gaffney, Dr Maria Ttofi, Prof David P. Farrington


Earlier publications from a Jacobs Foundation-funded project established the effectiveness of school-based face-to-face bullying prevention programmes based on over 100 evaluations (Gaffney, Ttofi, & Farrington, 2019), estimating reductions of bullying perpetration by approximately 19-20% and school bullying victimisation by roughly 15-16%. Further work also established the effectiveness of school-based intervention programmes to reduce online bullying perpetration and victimisation based on 24 independent evaluations (Gaffney, Farrington, Espelage, Ttofi, 2019), estimating reductions of cyberbullying perpetration by approximately 10%-15% and cyberbullying victimisation by approximately 14%.

School-based antibullying programmes seem to be effective, but what works for whom? And under what circumstances? Our latest work (Gaffney, Ttofi, & Farrington, 2021) aims to address these major questions by investigating the most effective intervention components in the existing RCT and quasi-experimental evaluations. Meta-analytical subgroup comparisons analogous to ANOVA were computed to examine the relationship between the presence of specific components and the effectiveness in reducing bullying perpetration (n = 82) and victimization (n = 86). We found that the presence of a while-school approach, clear anti-bullying policies and classroom rules were significantly associated with reductions in bullying perpetration.

Evaluations that included individual work with victims, information for parents and informal peer involvement in bullying situations were also more strongly related with reductions in bullying prevalence. With regards to victimisation, the presence of informal peer involvement and information for parents were association with larger reductions in victimisation prevalence.


Sharing findings

Dr Maria Ttofi is sharing results from this work at an UNESCO expert panel on effective ways to address school violence, part of the International Day Against Violence and Bullying at School on November 4, 2021.

Dr Maria Ttofi is also giving a keynote at the 25th International Workshop on Aggression taking place at the University of Turku (November 5, 2021) on ‘Aggressive and antisocial behaviour: Latest intervention efforts and directions for future prevention’.


Key publication

Gaffney, H., Ttofi, M.M., & Farrington, D.P. (2021). What works in anti-bullying programs? Analysis of effective intervention components. Journal of School Psychology, 85, 37 – 56.