Lessons from Houston on the Benefits of Dual Immersion Programs for DLLs

The city of Houston, Texas is home to an increasing — and increasingly diverse — population. Demographic data bear out the claim that Houston is transforming “into the single most ethnically and culturally diverse large metropolitan region in the nation.”

Consider: 79 percent of residents under the age of 5 are minorities. So are 72 percent of the city’s 30–34 year olds. By contrast, whites are the majority population within the portions of the city’s population over the  age of 65. In other words, the younger the Houstonian, the more likely that they are a Latino, African-American or Asian. Within this ethnic diversity comes considerable language diversity: 46 percent of residents (older than the age of 5) speak a language other than English at home.

Houston’s schools have been responding to the city’s growing pluralism. Houston’s notable programs for dual language learners (DLLs)and their correspondingly strong outcomes, have recently drawn some media attention. The most recent flurry stems from a research brief by Sandra Alvear, who works with the Houston Education Research Consortium (HERC), that explores the impact of the Houston Independent School District’s (HISD) bilingual programs on the reading achievement of the district’s DLLs.

The Houston Independent School District (HISD) is home to about 64,000 dual language learners — that make up about 30 percent of the district’s total enrollment — who speak about 100 languages. Thanks to the state’s bilingual mandate — which specifies that any school district that enrolls more than 20 DLLs in the same grade level must offer a bilingual education program — the majority of HISD’s language learners are enrolled in some form of a bilingual education program.

Alvear’s brief analyzes differences between the efficacy of the various program models in use. Specifically, she compares students enrolled in the district’s transitional bilingual and dual immersion programs between the years 2007–2012. Transitional bilingual programs provide students with instruction in their home language with the goal of transitioning them into an English-only classroom. Additionally, in those years, HISD’s dual immersion programs included two-way immersion models that enrolled both DLLs and non-DLLs with the goal of developing bilingualism and biliteracy for both, and one-way immersion models that only enrolled DLLs.

Her study is mindful of the nuances within HISD’s bilingual program models. She tracked a cohort of DLL kindergartners through the end of fifth grade and examined differences in their Spanish-language reading growth and English-language reading achievement based on the type of bilingual program the students were enrolled in. Importantly, her sample also included DLL students whose parents opted out of bilingual education and were enrolled in English-only programs.

So what did she find? First, students enrolled in any type of bilingual program made gains in their Spanish-reading knowledge between kindergarten and third grade. In general, two-way immersion DLL students outperformed DLLs in other bilingual programs and demonstrated faster growth in their Spanish-reading skills. Second, students in two-way programs also had higher English reading achievement than their peers enrolled in other bilingual programs. Third, students who were in a dual immersion program for three or four years had the highest English reading scores overall. In other words, both the time spent in a bilingual program and the type of bilingual program mattered for DLL achievement.

A 2014 HISD evaluation of its bilingual programs came to a similar conclusion. ((HISD eliminated developmental one-way immersion programs last school year. The programs included in this evaluation were: dual immersion, transitional bilingual, pre-exit bilingual, heritage language and Mandarin bilingual)) That report also notes that dual immersion students outperformed students enrolled in other types of bilingual programs on both Spanish and English measures of academic achievement. It also adds several new data points. First, students enrolled in dual immersion outperformed the district average on the State of Texas Assessments of Academic Readiness (STAAR) mathematics assessment.  Additionally, DLLs enrolled in dual immersion also demonstrated more improvement and growth in their English language proficiency in comparison to students in other bilingual programs. In other words, participation in dual immersion programs helped students maintain and enhance their knowledge of their home language, strengthen their English language skills, and acquire stronger reading and mathematics skills. That’s a compelling set of outcomes.

A growing body of research suggests that bilingual instruction produces better academic outcomes for dual language learners. So it’s not entirely surprising that these Houston studies found similarly positive results. But Alvear’s study and HISD’s report highlight that two-way immersion programs are especially beneficial for DLLs. They also indicate that Houston could very well be a model for how to design and implement policies that embrace students’ diverse cultural and linguistic assets.

These findings are not falling on deaf ears — since 2012, the number of schools offering dual immersion programs in the district has grown from 12 to 31 and they plan on expanding their dual language program to an additional 21 schools next year. And that's good news for their DLLs: last school year, only 1,748 DLLs were enrolled in dual immersion, while 29,715 were in the transitional bilingual program.


This post is part of New America’s Dual Language Learners National Work Group. Click here for more information on this team's work. To subscribe to the biweekly newsletter, click here, enter your contact information, and select "Education Policy.""


Amaya Garcia is a senior researcher in the Education Policy program at New America where she provides research and analysis on policies related to dual language learners.