This supplement contains documentation on the explicit and implicit stratification variables included in the TIMSS 2011 data files. The explicit strata are smaller sampling frames, created from the national sampling frames, from which national samples of schools were drawn. The implicit strata are nested within the explicit strata, and were used…

We evaluated the effects of one year of schoolwide cluster grouping on the academic achievement growth of gifted and non-identified elementary students using a piecewise multilevel growth model. Scores from 186 non-identified and 68 gifted students' Measures of Academic Progress Reading and Math scores were examined over three school years. In…

This article examines the effects of one year of exposure to "Learning to Read in a Healing Classroom" (LRHC) on the reading and math skills of second- to fourth-grade children in the low-income and conflict-affected Democratic Republic of the Congo. LRHC consists of two primary components: teacher resource materials that infuse…

Using reliable and valid measures of students' outcomes which are sensitive to change is critical for obtaining interpretable and therefore useful results from evaluations of school-based interventions. While measurement development for use in experimental evaluations receives a great deal of attention in the U.S., it lags behind in low-income…

An increasing number of schools are implementing gifted cluster grouping models as a cost-effective way to provide gifted services. This study is an example of comparative action research in the form of a quantitative case study that focused on mathematic achievement for nongifted students in a district that incorporated a schoolwide cluster…

This study involved the investigation of the effects of the Total Cluster Grouping Model on the achievement and identification of urban, elementary students and to learn about the classroom practices of and perceptions classroom teachers had of their students' ability levels over the course of the study. Proportionality of representation in…