The effectiveness of parent-implemented language interventions: a meta-analysis.

PURPOSE The purpose of this meta-analysis was to systematically evaluate the effects of parent-implemented language interventions on the language skills of children between 18 and 60 months of age with primary and secondary language impairments. METHOD A systematic literature search yielded 18 studies that met the predetermined inclusion and exclusion criteria. Effect sizes for each study were calculated for 7 language outcome variables and analyzed using a random effects model. Separate analyses were conducted for each language outcome and for each comparison group. Outcomes were compared for children with and without intellectual disabilities and for parent report and direct observational language measures. RESULTS The results indicate that parent-implemented language interventions have a significant, positive impact on receptive and expressive language skills of children with and without intellectual disabilities. Effect sizes (g) for child measures ranged from -0.15 to 0.82 depending on the outcome measure and comparison group. CONCLUSION The results of this review indicate that parent-implemented language interventions are an effective approach to early language intervention for young children with language impairments. Critical features of parent-implemented interventions are discussed in terms of implications for practice and future research.