NoTrap! was the most effective program for reducing bullying victimization, while ViSC and fairplayer.manual showed non-significant negative effects¶

Claim · All claims
Evidence · 1 study (2 entries) · quant-synthesis r2 · q4
Currency · newest study 2019 · checked against its sources 2026-10-17 (automated, 2 of 2 entries) · not reviewed by a person

Subclaims¶

Reading the evidence codes

q is the design tier, i the impact, n the sample, and the kind with its r the rigour judged within that kind: what each code means.

This claim: no standardized effect is recorded in observations/ for it yet, so no benchmark reading is possible.

q4 i? NoTrap! was the most effective anti-bullying program for reducing bullying victimization, followed by Bully Proofing Your School. → Hannah Gaffney 2019 q4 i? The fairplayer.manual and ViSC programs showed negative (non-significant) effects on perpetration, and ViSC was the only program associated with increases in both outcomes. → Hannah Gaffney 2019 (2)

Evidence¶

Hannah Gaffney 2019¶

Hannah Gaffney, David P. Farrington, & Maria M. Ttofi. (2019). Examining the Effectiveness of School-Bullying Intervention Programs Globally: a Meta-analysis. International Journal of Bullying Prevention. https://doi.org/10.1007/s42380-019-0007-4

q4 · i? · quant-synthesis · r2

Program-specific meta-analysis (Table 4): NoTrap! (n = 4) OR = 1.84 for victimization; the authors report NoTrap! reduced victimization "by around 37%" across evaluations.

"In relation to school-bullying victimization outcomes, NoTrap! was the most effective anti-bullying program, followed by the Bully Proofing Y our School Program."

Hannah Gaffney 2019 (2)¶

q4 · i? · quant-synthesis · r2

Program-specific results (Table 4): ViSC (n = 5) OR = 0.95 for both outcomes; the authors report ViSC "was the only program to increase bullying perpetration (by roughly 4%) and bullying victimization (by roughly 4%)."

"Surprisingly, negative effects were found for two anti-bullying programs, the fairplayer manual and ViSC, although these effects were not statistically significant."

Discussion¶

Learner Variables¶

Safety — outcome: instruction changes it

Program effectiveness varies by country: Greece led for perpetration, Italy for victimization — related
Effectiveness of anti-bullying programs varies significantly across evaluations (heterogeneity) — a broader claim this one bears on
School-based anti-bullying programs reduce bullying perpetration and victimization globally — a broader claim this one bears on
Work with peers in anti-bullying programs is associated with an increase in victimization — related
The Olweus Bullying Prevention Program produced the largest effect sizes for bullying perpetration, with effectiveness varying between Norway and USA evaluations — related
School-based anti-bullying programs decrease victimization by 17-20% on average — a broader claim this one bears on
School-based anti-bullying programs are effective overall, decreasing bullying by 20-23% on average — a broader claim this one bears on
Regional differences in program effectiveness: North America led for perpetration, Scandinavia for victimization, with no clear overall pattern — related

Page metadata

Field	Value
`type`	`claim`
`id`	`notrap-most-effective-victimization-visc-negative`
`title`	`NoTrap! was the most effective program for reducing bullying victimization, while ViSC and fairplayer.manual showed non-significant negative effects`
`description`	`NoTrap!`
`status`	`review`
`evidence_strength`	`moderate`
`newest_evidence`	`2019`
`source_checked`	`2026-10-17`
`generated`	by `process:wiki-ingest` on `2026-10-15`
`trust`	unverified — no one has confirmed this page's content
`sources`	2 — `hannah-gaffney-2019`, `hannah-gaffney-2019-2`

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