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Version 1.1 – Updated August 2021

Bullying

Overview

  • Influence: Bullying
  • Domain: Classroom
  • Sub-Domain: Classroom influences
  • Potential to Accelerate Student Achievement: Likely to have a negative impact
  • Influence Definition: Bullying is an ongoing and deliberate misuse of power in relationships through repeated verbal, physical, and/or social behavior that intends to cause physical, social, and/or psychological harm. It can occur in person, online, by individuals, or by groups.

Evidence

  • Number of meta-analyses: 4
  • Number of studies: 70
  • Number of students: 29,552
  • Number of effects: 70
  • Effect size: -0.33

Meta-Analyses

Meta-Analyses
Journal Title Author First Author's Country Article Name Year Published Variable Number of Studies Number of Students Number of Effects Effect Size
Social Development Nakamoto & Schwartz USA Is Peer Victimization Associated with Academic Achievement? A Meta-analytic Review 2009 Peer victimization on achievement 33 29,552 33 -0.24
Psychological Bulletin Kowalski, Giumetti, Schroader, & Lattanner USA Bullying in the digital age: A critical review and meta-analysis of cyberbullying research among youth 2014 Cyberbullying 6 0 6 -0.09
Review of Educational Research Gardella, Fisher, & Teurbe-Tolon USA A Systematic Review of Meta-Analysis of Cyber-Victimization and Educational Outcomes for Adolescents 2018 Cyber-bullying 25 0 25 -0.28
World Journal of Psychiatry Moore, Norman, Suetani, Thomas, Sly, & Scott USA Consequences of bullying victimization in childhood and adolescence: A systematic review and meta-analysis 2017 Bullying on achievement 6 0 6 -0.73
TOTAL/AVERAGE 70 29,552 70 -0.33

Confidence

The Confidence is the average of these four measures, each divided into five approximately equal groups and assigned a value from 1 to 5 based on the following criteria:

  • Number of Meta-analyses
    • 1 = 1
    • 2 = 2–3
    • 3 = 4–6
    • 4 = 7–9
    • 5 = 10+
  • Number of Studies
    • 1 = 1–10
    • 2 = 11–50
    • 3 = 51–200
    • 4 = 201–400
    • 5 = 400+
  • Number of Students
    • 1 = 1–2,500
    • 2 = 2,501–10,000
    • 3 = 10,000–20,000
    • 4 = 20,000–100,000
    • 5 = 100,001+
  • Number of Effects
    • 1 = 1–100
    • 2 = 101–300
    • 3 = 301–600
    • 4 = 601–1,200
    • 5 = 1,200+
Confidences
Number of Meta-Analyses Number of Studies Number of Students Number of Effects Overall Confidence
Confidence Factor 3 3 4 1 3
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