A new research brief by Jennifer L Steele and colleagues, published by the RAND Corporation, presents new research on dual-language immersion (DLI) programmes. These programmes provide both native English speakers and children learning English as an additional language (EAL) with general academic teaching in two languages from kindergarten (Year 1) onwards.
In partnership with the American Councils on International Education and the Portland Public Schools in Oregon (PPS), the authors conducted a random-assignment study of DLI education. The goal was to estimate the causal effects of the district’s DLI programmes on pupil performance over time in reading, mathematics and science, and on EAL pupils’ reclassification as English proficient.
PBS allocates immersion slots using a random-assignment lottery process for those who apply to the programmes. The study focused on 1,625 DLI lottery applicants in the kindergarten cohorts from 2004–2005 to 2010–2011. Pupil achievement was tracked until 2013–2014.
Key findings of the study were as follows:
- PPS pupils randomly assigned to dual-language immersion programmes outperformed their peers on state reading tests by 13% of a standard deviation in grade 5 (Year 6) and by 22% of a standard deviation in grade 8 (Year 9).
- Immersion-assigned pupils did not show statistically significant benefits or deficits in terms of mathematics or science performance.
- There were no clear differences in the effects of dual-language immersion according to pupils’ native language.
- EAL pupils assigned to dual-language immersion were more likely than their peers to be classified as English proficient by grade 6 (Year 7). This effect was mostly attributed to EAL pupils whose native language was the same as one of the two languages taught.
Source: Dual-language immersion programs raise student achievement in English (2017), RAND Corporation Research Brief, RB-9903