This study examined bias reduction in the eight nonequivalent comparison group designs (NECGDs) that result from combining (a) choice of a local versus non-local comparison group, and analytic use or not of (b) a pretest measure of the study outcome and (c) a rich set of other covariates. Bias was estimated as the difference in causal estimate…

This article reports the results of a randomized control trial of a semester-long intervention designed to promote ninth-grade science students' use of text-based investigation to create explanatory models of biological phenomena. The main research question was whether the student participants in the intervention outperformed the students in the…

The present study examined the effectiveness of the oral history approach with respect to students' historical competence. A total of 35 ninth-grade classes (N = 900) in Germany were randomly assigned to one of four conditions--live, video, text, or a (nontreated) control group--in a pretest, posttest, and follow-up design. Comparing the three…

This study explores preliminary results from a pedagogical intervention designed to improve instruction for all students, particularly emergent bilinguals in the United States (or English language learners). The study is part of a larger efficacy randomized controlled trial (RCT) of the Instructional Conversation (IC) pedagogy for improving the…

Using a randomized controlled trial, we tested a new teacher professional development program for increasing the language and literacy skills of young Latino English learners with 45 teachers and 105 students in 12 elementary schools. School-based teams randomly assigned to the intervention received professional development focused on cultural…

The authors evaluated the effects of P-SELL, a science curricular and professional development intervention for fifth-grade students with a focus on English language learners (ELLs). Using a randomized controlled trial design with 33 treatment and 33 control schools across three school districts in one state, we found significant and meaningfully…

In this study we examine the interplay between curriculum-embedded formative assessment--a well-known teaching practice--and general features of classroom process quality (i.e., cognitive activation, supportive climate, classroom management) and their combined effect on elementary school students' understanding of the scientific concepts of…