Skip Navigation
Funding Opportunities | Search Funded Research Grants and Contracts

IES Grant

Title: Examining Heterogeneity in English Learner Program Effects With Meta-Analysis
Center: NCER Year: 2020
Principal Investigator: Williams, Ryan Awardee: American Institutes for Research (AIR)
Program: Policies, Practices, and Programs to Support English Learners      [Program Details]
Award Period: 2 years (07/01/2020 – 06/30/2022) Award Amount: $599,829
Type: Exploration Award Number: R305A200082

Co-Principal Investigators: Garrett, Rachel; Polanin, Joshua

Purpose: Researchers in this study conducted a systematic review to identify rigorous studies of interventions aimed to improve English learner (EL) student learning outcomes and meta-analyze the studies. Researchers used meta-analysis to identify factors related to program effectiveness including characteristics of the studies and their methods, program features, outcome characteristics, sample characteristics, and study settings.

Project Activities: The research team identified 83 randomized control trials that met the study's inclusion criteria and used meta-analysis to identify malleable factors that explain program effectiveness.

Pre-registration Site: OSF | Exploring Heterogeneity in English Learner Intervention Effects with Meta-Analysis [NOTE: this was not a formal preregistration, but the researchers provided their study protocol, data, and code through Open Science Foundation]

Key Outcomes : This section will be updated when key outcomes are published.

Structured Abstract

Setting: The systematic review included 83 studies that evaluated programs designed to support ELs set in school settings (prekindergarten through 12th grade) using a randomized control trial design.

Sample: The sample included 83 studies and 819 effect sizes.

Interventions: The researchers included studies that evaluated the impact of a program designed to support EL student learning. Eligible programs included those with the explicit goal of improving EL student learning and achievement outcomes.

Research Design and Methods: Researchers included studies that used a randomized controlled trial design.

Control Condition: Studies included a treatment-as-usual or no-treatment control condition. Studies that used a one-group, pretest-posttest design were excluded.

Key Measures: Researchers included studies that measured EL students' English language development, literacy, mathematics, science, and social studies learning outcomes.

Data Analytic Strategy: Systematic review and meta-analysis, including correlated and hierarchical random effects meta-regression with robust variance estimation, were the primary methods used to implement this study.

Products and Publications

ERIC Citations: Find available citations in ERIC for this award here.

Publicly Available Data: OSF | Exploring Heterogeneity in English Learner Intervention Effects with Meta-Analysis

Project Website:

Select Publications:

IES Research Blog

Williams, R. (2023, April 24). English Learners: Analyzing What Works, for Whom, and Under What Conditions? Inside IES Research.


Williams, R. T., Garrett, R., Polanin, J., R., Zhang, Q., Hsin, L., Augilera, C., Cohen, E., Hoon Lee, D., Majeika, C., and Sejdijaj, A. (2022). Examining heterogeneity in English Learner program effects with meta-analysis. Poster presented at the annual conference of the Association for Education Finance and Policy, Denver, CO.