The Application of Effect Sizes in Research on Children and Families: Understanding Impacts on Academic, Emotional Behavioral and Economic Outcomes
Effect sizes are increasingly applied to describe the magnitude of findings about program effectiveness across a range of policy contexts. Though more researchers are recognizing the importance of including effect sizes in manuscripts, at times these effect sizes are calculated and interpreted without caution. For example, many papers base judgments on the import of effect sizes solely on Cohen’s original guidelines, not taking into account multiple other factors influencing the interpretation of effect sizes. Similarly, at times effect sizes are calculated incorrectly, providing inaccurate estimates of effects. In addition, attempts to use effect sizes to compare program effectiveness sometimes fail to consider the comparability of study design, population, and contextualization. To address these issues the Administration for Children and Families and federal partners convened a roundtable in 2007, Application of Effect Sizes in Research on Children and Families. The presentations by experts in the fields of methodology, statistics, epidemiology, economics and evaluation provided foundational understanding of effect sizes including their purpose, calculation and interpretation, critically examined the factors affecting the interpretation of effect sizes and made recommendations about the use of effect sizes in policy-relevant research with children and families.