This search yielded 43 articles reporting on 55 studies and 181 effect sizes. Exclusionary coding was conducted on 8033 abstracts from published and grey literature to yield a sample of high quality experimental and quasi-experimental work. Though thousands of worked examples studies have been conducted to date, a corresponding meta-analysis has yet to be published. The current meta-analysis quantifies the average effect of worked examples on mathematics performance from elementary grades to postsecondary settings and to assess what moderates this effect.