Linguistic complexity in second language writing: Insight from studies on task planning

Abstract Task planning and its effect on the complexity of second language (L2) written production have been studied extensively. However, the results of these studies are inconclusive, and at times contradictory, potentially as a result of variation in metrics of linguistic complexity. This study is an extension of earlier research syntheses and quantitative meta-analyses on the effects of planning on oral and written L2 production. It examines the identification and selection of linguistic complexity metrics in previous research on planning and its subsequent effects on the linguistic complexity of written L2 production. This research-focused synthesis of studies surveys construct definitions and operational definitions of linguistic complexity in the research domain and provides an overview of rationales for metric selection in the included studies. Methodological implications for future research are discussed in light of the findings.