The paradigm of evidence-based education continues to inform the development of policy in a number of countries. At its simplest level, evidence-based education incorporates evidence, often that provided by randomised controlled trials, into classroom practice. England's Education Endowment Foundation is in the process of exporting evidence-based…

"Attrition" is the loss of sample during the course of a study. It occurs when individuals initially randomly assigned in a study are not included when researchers examine the outcome of interest. Attrition is a common issue in education research, and it occurs for many reasons. The What Works Clearinghouse (WWC) is an initiative of the…

Meeting the What Works Clearinghouse (WWC) attrition standard (or one of the attrition standards based on the WWC standard) is now an important consideration for researchers conducting studies that could potentially be reviewed by the WWC (or other evidence reviews). Understanding the basis of this standard is valuable for anyone seeking to meet…