Dating violence (DV) profoundly impacts the physical and mental health of young adults. While bystander actions influence the continuation or termination of violent acts, research on the effectiveness of theory-based, particularly web-based, interventions remains limited. The purpose of this study is to evaluate the effectiveness of a web-based DV bystander education program grounded in the bystander theory and the theory of planned behavior. The program aimed to enhance college students' helping attitudes, subjective norms, perceived behavioral control, and helping intentions, while also addressing misconceptions about DV. We employed a quasi-experimental, two-group pretest-posttest design with repeated measures. Participants (N = 325) were recruited from three universities in central and southern Taiwan, with 162 assigned to the experimental group and 163 to the control group. The experimental group received the web-based program, while the control group received no intervention. Data were collected through self-administered questionnaires at pretest, posttest, and 2-month follow-up. Intervention outcomes were assessed using generalized estimating equations (GEE), adjusting for baseline differences in bystander experience as a time-invariant covariate; 2-month follow-up analyses evaluated changes from baseline. Findings revealed significant short-term improvements in helping attitudes, subjective norms, perceived behavioral control, and helping intentions. However, only helping attitudes were sustained at the 2-month follow-up. No significant reduction in misconceptions about DV was observed, possibly due to already low baseline scores. These results suggest that web-based programs may enhance short-term awareness and helping intentions among college students. To promote long-term change, additional strategies-such as on-campus advocacy and supportive peer environments-are needed to help sustain students' helping intentions over time.
Keywords: DV prevention program; bystander theory; helping intentions; misconceptions; theory of planned behavior.