The UALR Center for Literacy received a $1.7 million grant from the U.S. Department of Education to expand its Reading Recovery program. The grant is part of a $45.5 million effort by the U.S.D.E. to fund “what works in education” over a five-year period. The “Reading Recovery: Scaling Up What Works” project is a collaboration of 15 institutions of higher education with The Ohio State University as the lead institution and the University of Pennsylvania as the outside evaluation. The study involves two parallel designs – a randomized experiment and a regression discontinuity quasi-experiment, both of which are multi-site with thousands of students as the units of assignment, nested within hundreds of schools. The size and scope of the sample, combined with rigorous multi-site impact evaluation design make this study quite unique. Indications of variation in program contexts, supports, and components derived from these data are also used to explore potential predictors of variation in program impacts in subsequent statistical analyses of student reading achievement scores.