Closing Early Vocabulary Gaps: A Meta-Analysis of Interventions for Children Facing Elevated Risk For Challenges in Language Development

Vocabulary knowledge is essential for language development and a strong predictor of later academic achievement. Substantial disparities in vocabulary in the language of instruction are evident at the beginning of formal schooling, especially among children with increased risk for challenges in language development because of low socioeconomic status, limited proficiency in the language of instruction, ethnicity different from the majority, diagnosed language impairment or language delay. This meta-analysis synthesized findings from 30 interventions ( N = 4,184 students; 109 independent effect sizes) that evaluated vocabulary interventions for children facing elevated risk for challenges in language development aged 4;0 to 7;11 years. A multilevel meta-analysis revealed a moderate overall effect of vocabulary interventions (Hedges’ g = 0.62) and moderation effects by type of control group (alternate treatment vs. business-as-usual treatment) and outcome (proximal, researcher-developed vs. distal, standardized test). Business-as-usual treatment yielded larger effect sizes than alternate treatment. Further, using proximal, researcher-developed tests indicated higher effect sizes than distal, standardized tests. The results underscore the importance of systematic vocabulary interventions in formal educational settings. Implications for future research and practice are discussed.