The effectiveness of a professional development intervention to support children's language learning in diverse early childhood education and care settings in Norway

This study examines the effectiveness of a multicomponent professional development (PD) intervention, including collaboration with parents, in enhancing language learning among children in diverse Norwegian Early Childhood Education and Care (ECEC) settings. Utilizing a cluster-randomized design, data from 887 children (ages 1.5-4 years; 51% boys, 53% dual-language learners) across 56 centers indicated significant improvements in targeted language skills after 18 months of intervention (pretest August to October 2021 and posttest May to June 2023; d = 0.19, p < .001). No main effects were found in more distal language skills. Most outcomes in the intervention group were influenced by the level of implementation adherence both in classrooms and at home, suggesting that multicomponent, sustainable PD models in ECEC can support language learning.