District analysis: Dual language immersion yields similar growth to non‑DLI classrooms; home‑boundary availability strongly predicts enrollment

Provo City School District staff presented an 11‑year longitudinal analysis of dual language immersion (DLI) programs to the school board on May 13 and told members the data do not show a clear academic-growth advantage for DLI students compared with peers in non‑DLI classrooms after controlling for observable covariates.

Director of Assessments Nate Mitchell said the analysis used hierarchical linear modeling to control for socioeconomic status, multilingual learner (ML) status, special education status and other covariates. Using Acadience (DIBELS-type) subtest scaled scores from grades 3–6 as the longitudinal outcome, Mitchell said the district’s models showed no statistically significant growth advantage for DLI students overall. "Comparing DLI programs to non‑DLI programs, the growth rates are exactly the same," he said.

Mitchell highlighted one…