| There were an increasing number of immersion education programs available to elementary students in the United States. The most commonly available designs were 50:50 and 90:10, with Spanish and English being the languages of instruction. Further research was needed to determine the impact of immersion program design on students' academic and linguistic development. Research disaggregated by the students' primary language was also needed to determine whether program design influence was consistent across language groups. The purpose of this study was to compare the English language proficiency of English and Spanish L1 students enrolled in 50:50, 90:10 and English-only monolingual settings. A quantitative research study was conducted, in which students' achievement on the Smarter Balanced Assessment and California English Language Development Test were disaggregated by primary language group and instructional program, and compared for statistically significant differences. Results were analyzed to determine deviations in program influence. The covariate-matched samples were drawn from comparable schools in southern California, with 20 students representing each language group (English, Spanish) across each instructional setting (50:50, 90:10, and English only). |
