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Dual Immersion

Dual Immersion

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Two-Way Bilingual Immersion (TWBI) programs integrate language minority students (English learners) and language majority students (English speakers) in order to develop their bilingualism and biliteracy in English and another language. TWBI programs promote bilingualism and biliteracy, grade level academic achievement, and positive cross-cultural attitudes and behaviors in all students. These goals are described in the publication by Kathryn Lindholm-Leary, Ph.D., in Biliteracy for a Global Society: An Idea Book on Dual Language Education, (2000) Washington, D.C., National Clearinghouse for Bilingual Education. 


Early TWBI programs in California were established during the 1980’s. The California Department of Education, in 1994, started collecting data about the 47 existing programs. The most recent collected data is available in the Two-Way Bilingual Immersion Program Directory. A built-in search function makes it possible to identify programs by county, district, school, language. and materials. A print version (PDF; 202KB; 46 pp.) of this directory is also available. Last year, a total of 101 school districts reported placement of students in 224 programs.

A key decision in initiating a TWBI program is the choice of a program model. There are two common program models in California:

  • 90/10: Typically at a kindergarten level, 90 percent of the day is taught through the non-English language. English is used for a minimum of ten percent of the time. Percentage of non-English instruction decreases annually until both English and the target language are used equally. There are 111 programs of this type.
  • 50/50: Both English and the target language are used 50 percent of the time during the entire program. There are 61 programs.

In both models, instruction is delivered in and through the two languages; however, only one language at a time. Two-way bilingual immersion programs combine a maintenance bilingual education with a foreign language immersion model and minimally last from five to seven years.