Systematic Review on Effective Language Interventions

The development of language skills is under pressure. The declining trend in reading performance points to a growing group of Dutch youth with insufficient literacy skills (Meelissen et al., 2023). Early investments in the language development of vulnerable students have the potential to reverse this trend. It seems to be widely acknowledged that early investments are crucial; the literature is rich with early language interventions. However, what is still lacking is a clear understanding of exactly what early language interventions focus on, which interventions prove to be effective, and under what circumstances.

This project provides insight into the current state of early language interventions for children with (or at risk of) language deficits. It answers the question of how current language interventions reduce language deficits. It is crucial to understand the effects these early language interventions have on different language skills and aspects of language, as well as which specific elements contribute to the effectiveness of an intervention. This understanding is of great value for educational practice in selecting the right interventions for students. For researchers, such an overview is essential to get a clear picture of the evidence and the areas where there is still insufficient knowledge in the literature.

Through an extensive systematic literature review, 192 high-quality international effect studies have been identified, evaluating 260 interventions. The effective interventions for children with language deficits aged between 2 and 9 years old are mapped out for two purposes. First, we map the focus of current language interventions. We show which language skills and aspects of language the interventions target and identify both the evidence and the gaps in the literature on language deficit interventions. Second, we map the elements of effective interventions to gain insight into the potential success of intervention elements.