The impact of online peer feedback on learning outcomes has been well-established in previous meta-analyses. However, considerable variations remain unexplained, emphasizing the need to better understand the underlying reasons for heterogeneity. In this study, a large-scale and cross-context dataset, comprising 20,879 students enrolled in 505 assignments within 243 courses at 76 different institutions, was employed. Meta-regression, multi-level modeling, and ANCOVA were used to examine the effect size of each peer feedback experience and explore the associated heterogeneity of effects across c...
