Meta-Analysis and Research Synthesis in Language Acquisition Research

Scholars in the field of second language acquisition (SLA) research have conducted numerous studies in different lines of inquiry. They have carried out their investigations quantitatively, qualitatively, and relatively more recently in a mixed method design format. Even though there are now hundreds of published studies in each of these formats, it has been, up to now, really difficult for scholars to draw unique and reliable conclusions based on these published results. This methodological hurdle as well as the pressing need in SLA research to scrutinize literature for more comprehensive conclusions has given rise to meta-analytic and research synthetic practices in the field. As appealing research methods, these are becoming increasingly more popular in the world of second language acquisition research (SLAR) in order to average the size of effect sizes reported across studies to theorize based on qualitative findings. In this work, we intend to familiarize the audience with both meta-analytic and research synthetic works, to enumerate the (dis)advantages of both, and to offer suggestions for the implementation of these techniques in future domestic SLA research. Where qualitative and quantitative research works in our field report different and sometimes contradictory findings, we attempt to show how meta-analysis and qualitative research synthesis may help. We hope to clarify how systematic review of qualitative and quantitative research can differ from the normal literature review in SLA.

Keywords:

Meta-analysis , SLA , Research synthesis , EFL