Abstract
This cluster-randomized controlled study examined dual language learners (DLLs) in Norway who received a book-based language intervention program. About 464 DLLs aged 3–5 years in 123 early childhood classrooms participated in the study. The children were acquiring Norwegian as their second language in preschool and spoke a variety of first languages at home. They received a researcher-developed intervention that was organized around loosely scripted, content-rich shared reading in school and at home. Receiving the intervention had significant impacts on the children’s second-language skills (effect sizes of d = .25–.66). In addition to supporting second-language vocabulary and grammar, the program with its focus on perspective taking during shared reading resulted in impacts on children’s ability to shift perspectives and understand others’ emotional states.