Educational outcomes across multiple countries show large gaps between children's grade level curricular expectations and the actual learning levels of children. This paper discusses findings from an early grades literacy study and attempts to explore factors that potentially improve the English language learning results of Grades 3 and 4 learners…

This paper includes a nontechnical description of methods for calculating effect sizes in intellectual and developmental disability studies. Different hypothetical studies are used to illustrate how null hypothesis significance testing (NHST) and effect size findings can result in quite different outcomes and therefore conflicting results. Whereas…

This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

This paper outlines a method of determining the achieved relative strength (ARS) of an intervention by calculating the extent to which core intervention components are present in both the treatment and control condition. Using data from several examples the authors demonstrate how to calculate ARS indices, and subsequently how to incorporate them…

The National Job Corps Study was conducted in 1994-1996 to provide a thorough and rigorous assessment of the impacts of the Job Corps on key participant outcomes. To ensure that the study was well implemented, a study team from Mathematica Policy Research, Inc., (MPR) investigated outcome and admission (OA) procedures in each Job Corps region and…