Randomized controlled trials (RCTs) produce the most rigorous evidence of the impacts of interventions and other educational programs. However, it is rarely possible to collect all of the data for the entire sample: studies face missing data, often at multiple levels — such as the student and school levels. Abt Global and Chesapeake Research Associates conducted a study to describe, evaluate, test, and recommend methods appropriate for addressing missing data in randomized controlled trials in educational settings. The results, entitled “What to Do When Data Are Missing in Group Randomized Controlled Trials,” were published in a technical methods report. Read the final report.