1Universidad Estatal de Milagro, Milagro, Ecuador

Abstract

School bullying is an educational problem that affects school coexistence, perceived safety, and the conditions required for learning; consequently, prevention requires sustained institutional responses. The general objective was to evaluate the incidence of intervention strategies for preventing school bullying on academic achievement among upper-basic-education students. A quantitative quasi-experimental study with pretest-posttest measurement and a comparison group was conducted with an analytical sample of 180 students over four weeks. A 12-item five-point Likert instrument was administered, with six items addressing participation in prevention and six addressing academic achievement. Analyses included descriptive statistics, Cronbach’s alpha, Welch’s t test, Cohen’s d, and a linear model adjusted for pretest scores. Participation in prevention reached M = 3.354 (SD = 0.813), academic achievement reached M = 3.391 (SD = 0.537), and overall internal consistency was α = .877. At posttest, the intervention group obtained M = 71.405, whereas the comparison group obtained M = 64.230; the difference was statistically significant, t = 4.746, p < .001, with d = .708. After controlling for pretest scores, intervention condition was associated with an additional 7.481 points, 95% CI [6.061, 8.901]. The findings indicate that the preventive strategies were associated with better final academic performance and greater preventive participation. Nevertheless, the absence of random assignment requires interpretation within the limits of the quasi-experimental design and prevents definitive causal conclusions.