Cognitive task complexity and L2 written syntactic complexity, accuracy, lexical complexity, and fluency: A research synthesis and meta-analysis

This study, a research synthesis and quantitative meta-analysis, contributes to recent L2 writing research on task complexity and its impact on the syntactic complexity, accuracy, lexical complexity, and fluency (CALF) of written L2 production. Through a systematic analysis of task-based L2 writing research from 1998 to the present, the study aimed to better understand (a) how task complexity has been manipulated in previous research, (b) the range of metrics used in previous research to quantify L2 written CALF, and (c) the specific effects of task complexity manipulation on L2 written CALF. The results of the research synthesis indicate that a handful of task complexity features have received a great deal of attention compared to other, less studied task complexity features. Further, the results of the research synthesis suggest that many studies rely on relatively few metrics of CALF, often focusing on metrics of syntactic complexity associated with complex forms more typical of oral language production (Biber, 1988; Biber & Conrad, 2009; Biber & Gray, 2010; Biber, Gray, & Poonpon, 2011, 2013). The results of the quantitative meta-analysis indicate significant effects of increased resource-directing and resource-dispersing features of task complexity on the CALF of written L2 production. The results offer no clear support for the cognition hypothesis (Robinson, 2001, 2003, 2005, 2011), but rather suggest that features of task complexity may promote attention to the formulation and monitoring systems of the writing process (Kellogg, 1996; Kellogg, Whiteford, Turner, Cahill, & Mertens, 2013).