Project Activities
This study used original data collection and a randomized controlled design to explore the effects of grouping of English learners in the context of language- and discussion-based literacy instruction.
Structured Abstract
Setting
This study took place in 14 fourth and fifth grade classrooms in 6 elementary schools with high proportions of ELs in a large Northeastern city.
Sample
In each classroom, 6 ELs and 2 non-ELs participated. EL participants were selected based on being currently classified as English learners and scoring above the lowest two levels on the state English-as-a-second-language proficiency test. Across the 14 classrooms, a total of 112 students (84 ELs; 28 non-ELs) participated.
Research design and methods
Within each class, the researchers individually and randomly assigned ELs to linguistically homogeneous groups (with four ELs) or to linguistically heterogeneous groups (two ELs and two non-ELs per group). To control for instruction, all participants received the same small-group literacy intervention, but the format in which they received this intervention—heterogeneous or homogeneous groups—was randomly assigned to differ. Thus, the study yielded evidence on the effects of grouping in the context of intervention, rather than evidence for the efficacy of the intervention per se. Student outcomes were assessed before and after the 12-week intervention on targeted language skills (vocabulary, morphology), core analytic language skills, reading comprehension, and argumentative writing. Data on students' social networks were also collected before and after the intervention to assess effects of grouping on cross-linguistic social ties (ELs with non-ELs), number of ties, and strength of ties. Small groups were observed on 3 occasions and rated on a protocol to describe differences in instructional strategies for ELs, teacher talk, and student talk between heterogeneous and homogeneous groups.
Key measures
The project team administered researcher-developed measures of vocabulary and morphological awareness; a recently validated measure of academic language skills; Gates-MacGinitie and New York State reading comprehension tests; and a peer social network survey. The team also collected and analyzed observation data from small group activities.
Data analytic strategy
The researchers fit multiple regression models with clustered standard errors to account for students’ nesting within small groups. Models included a dummy variable for heterogeneous versus homogeneous groups, pretest covariates, and fixed effects of grade and schools. Moderation analyses explored whether effects differed by English proficiency using interaction terms. Descriptive analyses were used to explore how observed instruction differed between homogeneous and heterogeneous groups.
Key outcomes
The findings indicated no significant main effects of grouping. However, preregistered moderation analyses indicated that heterogeneous groups benefited students with higher English language skills (Hedges’ g = 0.27–0.59 or 0.75–1.93 grade equivalents), whereas homogeneous groups benefited students with lower English skills (g = 0.31–0.58 or 1.00–1.55 grade equivalents). There were no significant main or moderation effects for argumentation writing or social network outcomes. Instructional observations indicated that teachers provided more specialized strategies for ELs in homogeneous groups and more authentic questions for students in heterogeneous groups. Findings question the default use of homogeneous grouping and support considering English proficiency when making instructional and policy decisions for EL instruction (Kieffer et al., 2025)
People and institutions involved
IES program contact(s)
Project contributors
Products and publications
Researchers produced preliminary evidence published in peer-reviewed journals about the relationship between grouping strategies within the context of intervention delivery and student academic outcomes and peer networks.
Study registration:
Publications:
Eric Citations: Find available citations in ERIC for this award here.
Kieffer, M. J., & Weaver, A. W. (2024). Classroom Concentration of English Learners and Their Reading Growth. Educational Researcher, 53(1), 54-58.
Kieffer, M.J., Proctor, C.P., Weaver, A., Karbachinskiy, S., Chen, Q., Yu, Q., Solano, G., Coleman, A., Cavanaugh, S., Wu, X., Cappella, E., & Silverman, R. (2025). Effects of heterogeneous versus homogeneous grouping on English learners’ language and literacy development: Evidence from a randomized controlled trial. American Educational Research Journal, 62, 909-945https://doi.org/10.3102/00028312251355989
Weaver, A. W., Kieffer, M. J., Proctor, C. P., Cappella, E., Wu, X., Cavanaugh, S., & Karbachinskiy, S. (2025). The role of hang-out ties in reading comprehension and small group interactions for multilingual students. Reading Research Quarterly, 60, 1-14. https://doi.org/10.1002/rrq.70053
Additional project information
Additional online resources and information can be found at www.clavescurriculum.net.
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