Systematic Review and Meta-Analysis of Enhanced Milieu Teaching

Purpose: Early language intervention is essential for children with indicators of language delay. Enhanced milieu teaching (EMT) is a naturalistic intervention that supports the language development of children with emerging language. We conducted a systematic review and meta-analysis of all qualifying single­case and group design studies that evaluate the experimental effects of EMT on child outcomes. Method: We evaluated the risk of bias in the included studies and conducted a descriptive analysis of study quality, effect sizes, and demographics. We reviewed a total of 29 single-case and 17 group design studies in which 1,590 children participated. Results: Out of 46 studies, 39 met the What Works Clearinghouse standards without reservations, showing low levels of risk of bias. The effects were com­parable when EMT was implemented alone and when it was implemented with another intervention component, and EMT was more effective when imple­mented by caregivers than when implemented by therapists. Most studies did not report sufficient participant demographics. Conclusions: The EMT research literature published thus far is of high study quality; the effects across studies are comparable; and the intervention has been studied via a wide range of delivery modalities, contexts, implementers, and samples. Future research could systematically examine the effects of EMT and explore these varying intervention delivery, implementer, and learner char­acteristics as moderators.