Abstract:
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.