Interest in variation in program impacts--How big is it? What might explain it?--has inspired recent work on the analysis of data from multi-site experiments. One critical aspect of this problem involves the use of random or fixed effect estimates to visualize the distribution of impact estimates across a sample of sites. Unfortunately, unless the…

This What Works Clearinghouse (WWC) topic report addresses reading interventions for students in grades K-3, including core reading curricula, programs, or products to be used as supplements to other reading instruction, programs that focus on staff development, and literacy software. The WWC review on beginning reading focuses on programs…