No universal guideline exists for judging the practical importance of a standardized effect size, a measure of the magnitude of an intervention’s effects. This working paper argues that effect sizes should be interpreted using empirical benchmarks — and presents three types in the context of education research.
The Effect of Project GRAD on Elementary School
Student Outcomes in Four Urban Districts
This report describes the effects of Project GRAD, an ambitious education reform that targets high schools and the elementary and middle schools that feed into them, on student test scores in elementary schools in Houston, Texas; Atlanta, Georgia; Columbus, Ohio; and Newark, New Jersey.
Empirical Guidance for Studies That Randomize Schools to Measure the Impacts of Educational Interventions
This paper examines how controlling statistically for baseline covariates (especially pretests) improves the precision of studies that randomize schools to measure the impacts of educational interventions on student achievement.