In fact, Maria Ttofi and David Farrington (both from the University of Cambridge) conducted a more sophisticated analysis of forty - four
bullying prevention efforts (excluding
programs that targeted violence or aggression generally) and uncovered some promising evidence: ``... school - based anti-
bullying programs are effective: on average,
bullying decreased by 20 — 23 % and victimization
decreased by 17 — 20 %.»