Evaluating the Collaborative Strategic Reading Intervention: An Overview of Randomized Controlled Trial Options.

When attempting to determine if an intervention has a causal impact, the ‘gold standard’ of program evaluation is the randomized controlled trial (RCT). In education studies random assignment is rarely feasible at the student level, making RCTs harder to conduct. School-level assignment is more common but this often requires considerable resources compared to designs where classrooms can be assigned within a school. This article describes the costs and benefits of testing the effects of a classroom based instructional intervention using the multi-site cluster RCT. Topics covered include a discussion of various design options, statistical power, contamination, prior evidence, generalizability of results, ease of recruitment and need for data collection. The purpose of the article is to inform practice by providing program evaluators with an in-depth look at various RCT design options that were considered when searching for a way to efficiently evaluate a school-based intervention.