This article shows how assessment data such as that mandated by the No Child Left Behind Act can be used to examine the effectiveness of educational interventions and meet the Act's mandate for "scientifically based research." Based on the classic research design literature a cohort control group and a cohort control group with historical comparisons design are suggested as internally valid analyses. The logic of the "grounded theory of generalized causal inference" is used to develop externally valid results. The procedure is illustrated with published data regarding the Reading Mastery curriculum. Empirical results are comparable to those obtained in meta-analyses of the curriculum, with effect sizes surpassing the usual criterion for educational importance. Implications for school officials and policy makers are discussed.
Keywords Research designs • Cohort control groups • Assessment data • Evaluation researchFew would dispute that the No Child Left Behind (NCLB) Act has had an extraordinary influence on education in the United States. School administrators, teachers, and students have probably been most affected by the Act's focus on accountability and using standardized assessments to identify schools needing improvement. A key element of the Act was the requirement that states measure progress in reading and mathematics and compare students' scores to established benchmarks. Educational researchers have probably been more affected by the Act's requirement for "scientifically based research" and the call for "evidence-based practice."