The purpose of this study was to explore the effectiveness of an Orton-Gillingham-based reading instruction system, the Barton Reading and Spelling System (BRSS; Barton 2000), that was used as a supplemental reading instruction program for increasing the lower-level reading skills of a group of adolescents with persistent reading problems. Nine…

The purpose of this study was to investigate the effects of two learning contexts for explicit-reflective nature of science (NOS) instruction, socioscientific issues (SSI) driven and content driven, on student NOS conceptions. Four classes of 11th and 12th grade anatomy and physiology students participated. Two classes experienced a curricular…

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.…