Increased second language acquisition (SLA) research interest in the effect of planning on subsequent L2 oral production has typically examined the effect of planning on the syntactic complexity, accuracy, lexical complexity, and/or fluency (CALF) of L2 production. However, the results of research in this domain are inconclusive. This study, a…

The goal of this study was to determine the overall effects of pronunciation instruction (PI) as well as the sources and extent of variance in observed effects. Toward this end, a comprehensive search for primary studies was conducted, yielding 86 unique reports testing the effects of PI. Each study was then coded on substantive and methodological…

This article reports a meta-analysis of 42 experiments in 33 published studies involving processing instruction (PI) and production-based instruction (PB) used in the PI studies. The comparative effectiveness of PI and PB showed that although PI was more effective than PB for developing receptive knowledge, PB was just as effective as PI for…

This study reports a meta-analysis that synthesizes the empirical research on the role of language aptitude in second language grammar acquisition. A total of 33 study reports were identified including 17 predictive studies that investigated the correlations between aptitude and ultimate L2 attainment and 16 interactional studies that examined the…