The Playworks program, an initiative of the Robert Wood Johnson Foundation, places full-time coaches in low-income schools to provide opportunities for organized play during recess and throughout the school day. Using random assignment, Mathematica and the John W. Gardner Center for Youth and...

The Playworks program, an initiative of the Robert Wood Johnson Foundation, places full-time coaches in low-income schools to provide opportunities for organized play during recess and throughout the school day. Using random assignment, Mathematica and the John W. Gardner Center for Youth and...

Using measurement error models to analyze physical activity data collected from recess periods will allow for more accurate and reliable inferences on students' physical activity.