Towards evidence-based practice in language intervention for bilingual children.

UNLABELLED: Evidence-based practice requires that clinical decisions be based on evidence from rigorously controlled research studies. At this time, very few studies have directly examined the efficacy of clinical intervention methods for bilingual children. Clinical decisions for this population cannot, therefore, be based on the strongest forms of research evidence, but must be inferred from other sources. This article reviews the available intervention research on bilingual children, the current clinical recommendations for this population, and the strength of the empirical and theoretical support on which these recommendations are based. Finally, future directions are suggested for documenting current methods of intervention and developing optimal methods for different groups of bilingual children. Although the current research base is limited, the few studies available to date uniformly suggest that interventions that include a focus on both languages are superior to those that focus on only one language. The available research offers little guidance, however, as to the particular treatment methods that may be most appropriate. Further research is required to examine efficacy with larger numbers of children and children of various bilingual backgrounds. It is suggested that efforts to develop and test intervention methods for bilingual children must carefully consider the linguistic heterogeneity of bilingual children and the cultural variation in communication styles, child rearing practices, and child rearing beliefs. This will lead to the development of methods that may involve treatment methods that are more suitable for other languages and cultures. LEARNING OUTCOMES: Readers will become familiar with current recommendations for the treatment of bilingual children with language impairment, including which language or languages to use, the requirement for cultural sensitivity, and specific procedures that may be beneficial for bilingual populations. The heterogeneity of the bilingual population of children is highlighted. Readers will gain an understanding of the strength of research evidence backing up recommended practices, as well as of gaps in our current knowledge base and directions for further development and research.