The effects of recasts on L2 grammar: a meta-analysis

Abstract

ABSTRACT The present meta-analysis investigated the effects of recasts along with a number of moderating variables on L2 development by meta-analysing the results of 24 primary studies. The findings revealed an overall medium effect size for the effectiveness of recasts (g = 0.70, 95% CI = 0.48-0.93). Furthermore, the findings indicated that recasts are equally effective for the development of L2 explicit and implicit knowledge. The results also yielded strong effect sizes for the short-term and long-term effects of recasts in foreign language (FL) compared to second language (SL) contexts where weak effect sizes were obtained for both long-term and short-term effects of recasts. Contrary to expectations, the findings did not indicate a significant difference between the effectiveness of partial and full recasts. The findings of the present study, therefore, shed further light on the effectiveness of recasts and suggest that recasts are effective techniques for the development of implicit and explicit L2 knowledge in FL contexts. The findings indicate that instructional context plays the most significant role in the efficacy of recasts. The implications of the study and considerations for interpreting the results will be discussed in the paper in the light of some theoretical justifications as well as a number of limitations of the present meta-analysis.