Robert E. Slavin

Evidence-Based Education Policies: Transforming Educational Practice and Research

At the dawn of the 21st century, educational research is finally entering the 20th century. The use of randomized experiments that transformed medicine, agriculture, and technology in the 20th century is now beginning to affect educational policy. This article discusses the promise and pitfalls of randomized and rigorously matched experiments as a basis for policy and practice in education. It concludes that a focus on rigorous experiments evaluating replicable programs and practices is essential to build confidence in educational research among policymakers and educators. However, new funding is needed for such experiments and there is still a need for correlational, descriptive, and other disciplined inquiry in education. Our children deserve the best educational programs, based on the most rigorous evidence we can provide.

Ability Grouping and Student Achievement in Elementary Schools: A Best-Evidence Synthesis

This article reviews research on the effects of between- and within-class ability grouping on the achievement of elementary school students. The review technique—best-evidence synthesis—combines features of meta-analytic and narrative reviews. Overall, evidence does not support assignment of students to self-contained classes according to ability (median effect size [ES] = .00), but grouping plans involving cross-grade assignment for selected subjects can increase student achievement. Research particularly supports the Joplin Plan, cross-grade ability grouping for reading only (median ES = +.45). Within-class ability grouping in mathematics is also found to be instructionally effective (median ES = +.34). Analysis of effects of alternative grouping methods suggests that ability grouping is maximally effective when done for only one or two subjects, with students remaining in heterogeneous classes most of the day; when it greatly reduces student heterogeneity in a specific skill; when group assignments are frequently reassessed; and when teachers vary the level and pace of instruction according to students’ needs.

Best evidence synthesis: An intelligent alternative to meta-analysis

Research review has long been one of the most important scholarly activities in all branches of science. While there is sometimes a single study so well-designed, well carried out, and difficult to replicate that its findings are accepted as conclusive, more often there are many studies on a given topic, no one of which clearly supersedes the others. These studies may be done by different investigators using different methods or different populations. They may arrive at different conclusions. When this is the case, there is a need for reviewers to carefully consider the evidence and to put forth conclusions or hypotheses about where the weight of the evidence lies.

Achievement Effects of Ability Grouping in Secondary Schools: A Best-Evidence Synthesis

This article reviews research on the effects of ability grouping on the achievement of secondary students. Six randomized experiments, 9 matched experiments, and 14 correlational studies compared ability grouping to heterogeneous plans over periods of from one semester to 5 years. Overall achievement effects were found to be essentially zero at all grade levels, although there is much more evidence regarding Grades 7–9 than 10–12. Results were similar for all subjects except social studies, for which there was a trend favoring heterogeneous placement. Results were close to zero for students of all levels of prior performance. This finding contrasts with those of studies comparing the achievement of students in different tracks, which generally find positive effects of ability grouping for high achievers and negative effects for low achievers, and these contrasting findings are reconciled.

Best-Evidence Synthesis: An Alternative to Meta-Analytic and Traditional Reviews:

This paper proposes an alternative to both meta-analytic and traditional reviews. The method, “best-evidence synthesis,” combines the quantification of effect sizes and systematic study selection procedures of quantitative syntheses with the attention to individual studies and methodological and substantive issues typical of the best narrative reviews. Best-evidence syntheses focus on the “best evidence” in a field, the studies highest in internal and external validity, using well-specified and defended a priori inclusion criteria, and use effect size data as an adjunct to a full discussion of the literature being reviewed.

Learning to cooperate, cooperating to learn

This book was written and edited as a project of the International Asso- ciation for the Study of Cooperation in Education (lASCE). It grew di- rectly out of the second conference of the lASCE, held at Brigham Young University, Provo, Utah, in [uly 1982. The chapters in the book were originally presented in some form at the Provo conference, though most have been considerably revised since that time. This is the second book sponsored by the lASCE; the first, Cooperation in Education (Provo, Utah:Brigham Young University Press, 1980),edited by Shlomo Sharan, Paul Hare, Clark Webb, and Rachel Hertz-Lazarowitz, was based on the proceedings of the first conference of the IASCE in Tel Aviv, Israel, in 1979. The IASCE is a group of educators interested in studying, devel- oping, or applying cooperative methods at various levels of the process of education. It includes researchers, teacher educators, teachers, and school administrators from more than a dozen countries.

A Synthesis of Research on Language of Reading Instruction for English Language Learners

This article reviews experimental studies comparing bilingual and English-only reading programs for English language learners. The review method is best-evidence synthesis, which uses a systematic literature search, quantification of outcomes as effect sizes, and extensive discussion of individual studies that meet inclusion standards. A total of 17 studies met the inclusion standards. Among 13 studies focusing on elementary reading for Spanish-dominant students, 9 favored bilingual approaches on English reading measures, and 4 found no differences, for a median effect size of +0.45. Weighted by sample size, an effect size of +0.33 was computed, which is significantly different from zero (p < .05). One of two studies of heritage languages (French and Choctaw) and two secondary studies favored bilingual approaches. The review concludes that although the number of high-quality studies is small, existing evidence favors bilingual approaches, especially paired bilingual strategies that teach reading in the native language and English at different times each day. However, further research using longitudinal, randomized designs is needed to determine how best to ensure reading success for all English language learners.

Mainstreaming Students with Mild Handicaps: Academic and Social Outcomes

This paper reviews research on the effects of placing students with mild academic handicaps in full-time special education classes, part-time regular classes with resource support, and full-time regular classes. It also reviews research on the effects of programs designed to improve the achievement, social-emotional adjustment, and social acceptance of academically handicapped students by their nonhandicapped classmates. Methodologically adequate studies of placements of academically handicapped students indicate few consistent benefits of full-time special education on any important outcomes. The research favors placement in regular classes using individualized instruction or supplemented by well-designed resource programs for the achievement, self-esteem, behavior, and emotional adjustment of academically handicapped students. Experimental research indicates that cooperative learning and individualized instruction programs can improve the self-perceptions and behavior of mainstreamed academically handicapped students and acceptance by their nonhandicapped classmates.

Perspectives on Evidence-Based Research in Education—What Works? Issues in Synthesizing Educational Program Evaluations:

Syntheses of research on educational programs have taken on increasing policy importance. Procedures for performing such syntheses must therefore produce reliable, unbiased, and meaningful information on the strength of evidence behind each program. Because evaluations of any given program are few in number, syntheses of program evaluations must focus on minimizing bias in reviews of each study. This article discusses key issues in the conduct of program evaluation syntheses: requirements for research design, sample size, adjustments for pretest differences, duration, and use of unbiased outcome measures. It also discusses the need to balance factors such as research designs, effect sizes, and numbers of studies in rating the overall strength of evidence supporting each program.

The Cooperative Elementary School: Effects on Students’ Achievement, Attitudes, and Social Relations

This article reports the results of a 2-year study of the cooperative elementary school model which used cooperation as an overarching philosophy to change school and classroom organization and instructional processes. The components of the model include: using cooperative learning across a variety of content areas, full-scale mainstreaming of academically handicapped students, teachers using peer coaching, teachers planning cooperatively, and parent involvement in the school. After the first year of implementation, students in cooperative elementary schools had significantly higher achievement in reading vocabulary. After the second year, students had significantly higher achievement in reading vocabulary, reading comprehension, language expression, and math computation than did their peers in traditional schools. After 2 years, academically handicapped students in cooperative elementary schools had significantly higher achievement in reading vocabulary, reading comprehension, language expression, math computation, and math application in comparison with similar students in comparison schools. There also were better social relations in cooperative elementary schools, and handicapped students were more accepted socially by their nonhandicapped peers than were similar students in traditional schools with pull-out remedial programs. The results also suggest that gifted students in heterogeneous cooperative learning classes had significantly higher achievement than their peers in enrichment programs without cooperative learning.