This systematic review and meta-analysis appraised and synthesized mathematics interventions research addressing rational number concepts for students with mathematics difficulties (MD) in Grades 3-9. Included studies (n = 28) meet the What Works Clearinghouse Group Design standards (Version 4.0) for study quality. Across all studies, we found…

Magnitude understanding is critical for students to develop a deep understanding of fractions and more advanced mathematics curriculum. The research reports in this special issue underscore magnitude understanding for fractions and emphasize number lines as both an assessment and an instructional tool. In this commentary, we discuss how number…

Each of the five articles in this special issue gets "into the weeds" in terms of studying actual classroom or school implementation of evidence-based or promising practices. Virtually all confront the issue of logistics and establishing an infrastructure for ensuring adequate implementation. In general, those studies that ask teachers…

The goal of this randomized controlled trial (RCT) was to evaluate the effectiveness of a small-group intervention in fractions for fifth-graders who are performing below grade level in mathematics. The impact of the fractions intervention was assessed on fifth-grade at-risk students' understanding of foundational fractions concepts and procedural…

The purpose of this efficacy study was to examine the impact of the Teacher Study Group (TSG) professional development program in vocabulary, on teacher knowledge, observed teaching practice, and student vocabulary achievement, when implemented with first grade teachers in Title 1 schools. This multi-site cluster randomized trial was implemented…

The purpose of this replication study was to examine the impact of the Teacher Study Group (TSG) professional development in vocabulary on first-grade teachers' knowledge of vocabulary instruction and observed teaching practice, and on students' vocabulary knowledge. Sixty-two schools from 16 districts in four states were randomly assigned to…

This article describes key findings from contemporary research on screening for early primary grade students in the area of mathematics. Existing studies were used to illustrate the constructs most worth measuring and the diverse strategies that researchers used to study potential measures. The authors discussed the strengths and weaknesses of…

Replication studies are extremely rare in education. This randomized controlled trial (RCT) is a scale-up replication of Fuchs et al., which in a sample of 139 found a statistically significant positive impact for Number Rockets, a small-group intervention for at-risk first graders that focused on building understanding of number operations. The…

The main purposes of this study were to test the effects of teaching at-risk 4th graders to provide explanations for their mathematics work and examine whether those effects occur by compensating for limitations in cognitive processes. We randomly assigned 212 children to 3 conditions: a control group and 2 variants of a multi-component fraction…

Since 2007, when this technical report was originally issued, the assessment field has made considerable progress in developing valid and reliable screening measures for early mathematics difficulties. This update includes new research published since 2007. It focuses on valid and reliable screening measures for students in kindergarten and first…

The purpose of this study was to use meta-analysis to synthesize findings from randomized control trials and quasi-experimental research on instructional approaches that enhance the mathematics proficiency of students with learning disabilities. A search of the literature from January 1971 to August 2007 resulted in a total of 42 interventions (41…

When attempting to determine if an intervention has a causal impact, the "gold standard" of program evaluation is the randomized controlled trial (RCT). In education studies random assignment is rarely feasible at the student level, making RCTs harder to conduct. School-level assignment is more common but this often requires considerable resources…

Randomized field trials were used to examine the impact of the Teacher Study Group, a professional development model, on first grade teachers' reading comprehension and vocabulary instruction, their knowledge of these areas, and on the corollary comprehension and vocabulary achievement of their students. The multi-site study was conducted during…

This meta-analysis synthesizes experimental and quasi-experimental research on instruction that enhances the mathematics performance of K-12 students with learning disabilities. It reports the findings from this synthesis, discusses the implications for practice, and suggests next steps for research and professional development efforts in this…

This study sought to examine the effects of Tier 2 intervention in a multitiered model on the performance of first- and second-grade students who were identified as having mathematics difficulties. A regression discontinuity design was utilized. Participants included 126 (Tier 2, n = 26) first graders and 140 (Tier 2, n = 25) second graders. Tier…