Meta-analysis on the effect of enrichment programs on the academic achievement of gifted and talented students

Much research has been conducted about gifted education recently. One of the most applied interventions in gifted education is enrichment. Enrichment is the teaching and learning process that increases the depth and complexity of typical school subjects. In this thesis, the effects of enrichment on the academic achievement of gifted and talented students, was examined. The meta-analytic procedure was used to determine the overall effect size. The researcher used Education Resources Information Center database (ERIC), the most comprehensive database on education literature, Bilkent online library, and Google Scholar to detect relevant studies. The studies were filtered to the studies published between 2013 and 2021. After applying the inclusion and exclusion criteria, 22 studies were determined to be included in this meta-analysis. The pooled effect size was estimated under the random-effects model using the R statistical software. The effect size measure used was Hedges’ g. The findings showed that enrichment programs had a positive moderate effect (g= 0.68, 95% CI [0.31, 1.05]) on students’ academic achievement. To investigate the robustness of the findings, heterogeneity analyses were conducted and publication bias was investigated through the funnel plot. High heterogeneity (I2=84.6%) of the findings supports the use of a random-effects model. Also, the funnel plot showed an asymmetry which might be the reason for this heterogeneity and/or a possible publication bias found in the literature. In addition, subgroup analyses were performed to check for possible reasons for this high heterogeneity.