There is increasing interest in meta-analysis in different fields due to the need to combine the results of primary research. One of the crucial concepts in combining results is weighting. This study examines how Hunter and Schmidt's method, weighting by sample size; Hedges and Vevea's method, weighting by inverse variance; and Osburn and…

This synthesis extends a report of research on extensive interventions in kindergarten through third grade (Wanzek & Vaughn, 2007) to students in Grades 4 through 12, recognizing that many of the same questions about the effectiveness of reading interventions with younger students are important to address with older students, including (a) how…

This synthesis extends a report of research on extensive interventions in kindergarten through third grade (Wanzek & Vaughn, 2007) to students in Grades 4 through 12, recognizing that many of the same questions about the effectiveness of reading interventions with younger students are important to address with older students, including (a) how…

This article presents a meta-analysis of experimental and quasi-experimental studies in which intermediate and secondary students with learning disabilities were taught science content through the use of graphic organizers (GOs). Following an exhaustive search for studies meeting specified selection criteria, 23 standardized mean effect sizes were…

A vertical scale, in principle, provides a common metric across tests with differing difficulties (e.g., spanning multiple grades) so that statements of "absolute" growth can be made. This paper compares 16 states' 2007-2008 effect size growth trends on vertically scaled reading and math assessments across grades 3 to 8. Two patterns…

This report presents results from a new quantitative synthesis of research on the effectiveness and validity of test accommodations for English language learners (ELLs) taking large-scale assessments. In 2006, the Center on Instruction published a review of the literature on test accommodations for ELLs titled "Practical Guidelines for the…

Although some literacy researchers consider grouping students for reading instruction to be a proven educational practice, the support for this belief is lacking from a research synthesis perspective. With this idea in mind, Slavin comments in the middle of his review on the effects of grouping: "there is not enough research on within-class…

This article reports a synthesis of intervention studies conducted between 1994 and 2004 with older students (Grades 6-12) with reading difficulties. Interventions addressing decoding, fluency, vocabulary, and comprehension were included if they measured the effects on reading comprehension. Twenty-nine studies were located and synthesized.…