New Research Reveals Grouping English Learners Together Yields Little to No Benefit and May Harm Most Students

For years, K-12 schools have grouped English learners in classrooms, driven by factors including limited resources and the intention to provide targeted language instruction to students with similar educational needs. Despite this continued practice, there is a lack of evidence showing that separating English learners from their peers is effective.

In a new study, published in Peabody Journal of Education, researchers examined outcomes for English learners (ELs) grouped together in core academic courses in high schools and found that concentrating ELs was linked to lower rates of graduation and college enrollment.

“Many well-intentioned educators are trying to manage logistical complexities of staffing and scheduling,” says lead author Kristin Black, research scientist at the Institute for Human Development and Social Change at NYU Steinhardt. “We need to learn more about whether there are particular English learners who might be able to benefit from this kind of segregated course environment, but our latest study suggests that school leaders should be much more cautious about this practice.”

The findings build upon a growing body of research challenging grouping ELs together, including a study in the October 2025 issue of American Education Research Journal in which researchers tested the effects of teaching elementary school ELs in homogenous versus heterogenous groups and found no significant differences in academic outcomes for most students.

“Across these two studies and others, our findings challenge the default practice of separating English learners for instruction. While the details depend on student and school characteristics, we found little evidence that grouping English learners separately yields academic benefits for most students,” says NYU Steinhardt Professor Michael Kieffer, lead author of the AERJ study and a co-author of the study in PJE. “Furthermore, we found troubling evidence that it can have meaningful negative associations with later outcomes.”

In the latest study of high schoolers, Black and her co-authors analyzed New York City Public School data for 31,303 ELs enrolled as ninth graders in 2013, 2014, and 2015. Students were categorized into three groups based on their years learning English prior to ninth grade: newcomer EL (1-3 years), developing EL (4-6 years), and long-term EL (7 or more years). The researchers separated high schools into those whose EL populations were 50% or more, and those with less than 50%. They evaluated the role of EL concentration (measured by the percent of ELs in courses) on high school graduation rates in four and six years, and college enrollment (immediately after graduation or within 2.5 years after graduation).

They found that regardless of prior English learning and percentage of ELs in high schools, greater concentrations of EL students in courses were associated with lower likelihood of graduating high school and enrolling in college. Compared to students in low EL concentration courses, students in high EL concentration courses were:

• 10-15% less likely to graduate within four years
• 6-11% less likely to graduate within six years
• 12-13% less likely to enroll in college immediately after graduation
• 9-13% less likely to enroll in college within 2.5 years of graduation

In evaluating the effects of EL grouping in elementary schools, Kieffer and his co-authors randomly assigned 84 ELs in fourth or fifth grade to small groups composed of all ELs or groups with both ELs and non-ELs. The groups received the same 12-week language and literacy curriculum taught by the same teachers. Researchers assessed students’ performance in language skills, reading comprehension, and argumentative writing. They also observed the teachers to see how their implementation of the curriculum differed between the two types of groups.

Overall, the researchers did not find statistically significant differences for the average student in academic outcomes between groups. However, they found that heterogenous groups offered some benefits to students with higher English language skills, while homogeneous groups offered some benefits to students with lower English skills.

“When we observed heterogeneous groups, we saw teachers using more open-ended questions and promoting richer discourse, suggesting the benefits of these groups for most students,” says Kieffer. “At the same time, the subset of students at earlier levels in their English learning did benefit from being grouped homogeneously. This may be because teachers provided more targeted language instruction appropriate to their particular levels when teaching homogeneous groups. Nonetheless, these results suggest grouping English learners together should be done sparingly and strategically.” 

“English learners have a right to be integrated into the life of their school, and an important part of that experience is taking courses with English-proficient peers,” says Black. “These findings should push us to rethink what is often a default practice of scheduling English learners into separate classrooms.”

The Institute of Education Sciences, US Department of Education, provided funding for both the AERJ study (R305C200016) and PJE study (R305A200069).