The What Works Clearinghouse (WWC) identifies existing research on educational interventions, assesses the quality of the research, and summarizes and disseminates the evidence from studies that meet WWC standards. The WWC aims to provide enough information so educators can use the research to make informed decisions in their settings. This document guides study authors on how to describe their studies and report findings in a way that is clear and complete. This document also outlines specific reporting guidelines for randomized controlled trials and quasi-experimental studies, which are the two most common types of research designs in studies the WWC reviews.