Questions regarding the generalizability of results from educational experiments have been at the forefront of methods development over the past five years. This work has focused on methods for estimating the effect of an intervention in a well-defined inference population (e.g., Tipton, 2013; O'Muircheartaigh and Hedges, 2014); methods for…

This study investigated whether German learners of English as a foreign language (EFL) acquire additional recoding strategies that they do not need for recoding in the consistent German orthography. Based on the psycholinguistic grain size theory (Ziegler & Goswami, 2005) we expected students with little experience in EFL to use the same…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…