The effect of task complexity on integrated writing performance: The case of multiple-text source-based writing

Previous research on the effect of task complexity on L2 writing performance has been mostly concerned with independent writing, and there is a paucity of empirical findings on integrated writing tasks in this regard. Thus, the present research investigated the impact of multiple-document integration on source-based writing. Two groups, with comparable general language proficiency, independent writing ability, and integrated writing ability participated in this research. In the simple task, the students were supposed to summarise a single text, whereas the participants in the complex task were asked to write a summary for a three-passage text dealing with the same issue, which was more cognitively taxing. The results revealed that task complexity had a significant impact on some measures of syntactic complexity (mean length of clause, subordination, and mean number of modifiers per noun phrase), lexical diversity, and causal cohesion, had an adverse influence on accuracy, and had no significant effect on lexical sophistication. The implications of these findings for L2 writing research and pedagogy are offered.