New Study Shows Academic Benefits of Two-Way Immersion Programs for Miami’s English Learners

Miami School Readiness Project data suggests two-way immersion is associated with faster English language acquisition and higher achievement.
Blog Post
March 16, 2020

Almost five million English learners (ELs) are currently in our country’s public schools, and this number is growing. Schools are responsible for providing EL students with both academic instruction and language instruction to help them develop proficiency in English. While the pendulum has now swung in favor of bilingual education, some ELs are still subject to English-only instruction. These instructional models have typically been sold as ways to help EL students learn English as fast as possible.

However, a growing body of research suggests that participating in dual language programs, which support ELs’ home language development, actually promotes faster English acquisition than English-dominant models. And now, a recently published study bolsters these findings and provides additional evidence of the academic benefits of dual language programs.

Using data from Miami’s School Readiness Project (a large-scale project that collected longitudinal data on five cohorts of low-income Miami-Dade preschoolers), Ellen Serafini and co-authors Nadine Rozell and Adam Winsler analyzed outcomes for ELs in two-way immersion programs, which are designed to prepare bilingual, biliterate, and bicultural students. The dual language programs studied used English and the target language 50 percent of time, though some dual language programs may use a 60/40 or 90/10 model. These programs strive to maintain a student population that is half native speakers of the target language and half native English speakers.

At the time, schools in the Miami-Dade area offered six different types of instructional models for ELs. Researchers found that ELs who attended schools with two-way immersion programs had faster English language acquisition than students enrolled in other types of teaching models, such as those that maintain English-only instruction, as well as higher achievement on academic measures, including math and reading scores on statewide assessments and grade point average (GPA). Specifically, students in two-way programs met English proficiency criteria on their district’s English for Speakers of Other Languages (ESOL) assessment and exited EL status earlier than their peers in other programs.

Most notably, the study might provide an explanation as to why research consistently shows a positive association between dual language programs and academic outcomes. The researchers’ analysis found that faster English language acquisition mediated the relationship between two-way immersion programs and higher academic outcomes. In other words, it is possible that the reason ELs in two-way immersion programs appear to lead to more positive outcomes is that they help these students acquire English faster. This makes sense: once ELs achieve English proficiency it should be easier for them to reach the same academic content expectations as their monolingual peers.

The study also expands the body of research on dual language to include students who are rarely studied: low-income ELs living in a highly bilingual and bicultural environment. Whereas other studies have analyzed the impact of dual language programs in communities where the partner language is considered the “minority language,” 68 percent of Miami-Dade’s residents speak Spanish at home. The large number of Spanish-speaking residents has created a unique, truly multicultural environment in which Spanish is valued and widely used. To this end, the study confirms that the benefits of dual language programs seen in previous research also hold true for students living in a community that is largely Spanish-speaking.

Research that dual language programs are effective at helping ELs achieve English proficiency is mounting, and this research is critical to debunking the myth that the fastest way to English language proficiency is in an English-only environment. The question that remains is how other factors, such as dual language teachers’ practices, influence how well dual language programs work. If we more clearly understand the ways in which dual language programs enhance student outcomes, we can implement programs with the best chance of success.

Related Topics
Instructional Models for ELs