Bilingual and Home Language Interventions With Young Dual Language Learners: A Research Synthesis.

Purpose: The purpose of this systematic review was to determine what bilingual or home language interventions have been found to be effective for 2- to 6-year-old dual language learners who have language impairment (LI) or are at risk for LI.

Method: We conducted ancestral searches and searches of electronic databases, hand-searched article bibliographies, and searched 19 journals for experimental, quasiexperimental, or single-subject studies.

Results: The review yielded 26 studies that were coded for quality, frequency and duration of the intervention, number of participants, location of intervention, interventionist, language(s) of intervention, and reported or calculated effect sizes. Studies were grouped by those that focused specifically on at-risk populations and those that focused on children with LI. Emerging trends provide support for bilingual and/or home language interventions for both children with LI and those at risk for LI.

Conclusions: There were relatively few studies that met inclusion criteria, and the average quality rating for a study was 6.8 out of 9.0 possible points. More high-quality research is needed, particularly with populations that speak languages other than Spanish. Clinicians need more evidence-based recommendations to improve the language and literacy outcomes of the diverse range of dual language learners served in the United States and abroad.