Developing and maintaining a high-quality science teaching corps has become increasingly urgent with standards that require students to move beyond mastering facts to reasoning and arguing from evidence. "Effective" professional development (PD) for science teachers enhances teacher outcomes and, in turn, enhances primary and secondary…

Rigorous evidence of program effectiveness has become increasingly important with the 2015 passage of the Every Student Succeeds Act (ESSA). One question that has not yet been fully explored is whether program evaluations carried out or commissioned by developers produce larger effect sizes than evaluations conducted by independent third parties.…

Education researchers working in sub-Saharan Africa have recently and rapidly expanded the availability of evidence related to the impact of educational interventions on learning outcomes, particularly in preprimary and lower primary education (Ganimian & Murnane, 2016; McEwan, 2015; Popova, Evans, & Arancibia, 2016). Awareness that…

This article provides practical guidance for researchers who are designing studies that randomize groups to measure the impacts of educational interventions. The article (a) provides new empirical information about the values of parameters that influence the precision of impact estimates (intraclass correlations and R[superscript 2] values) and…