To estimate the effects of adaptive education on cognitive, affective, and behavioral outcomes of learning, 309 effect sizes were calculated using statistical data from 38 studies that contained a combined sample of approximately 7,200 students. The substantial mean of the study-weighted effect sizes is .45, suggesting that the average student in adaptive programs scores at the 67th percentile of control group distributions. The effects appear constant across grades, socioeconomic levels, races, private and public schools, and community types. In addition, the effects are not significantly different across the categories of adaptiveness, student outcomes, social contexts, and methodological rigor of the studies. (Author)