The development of syntactic complexity in integrated writing: A focus on fine-grained measures

Past studies on complexity development in L2 writing have largely examined syntactic complexity, measured by traditional length-based measures, in independent writing, rather than integrated writing. The present research adds to the literature by investigating the development of clausal and phrasal indices of syntactic complexity in two integrated writing tasks (graph writing and summary writing) via fine-grained measures. The participants wrote three graph-based essays in the first semester, and three summary writing essays in the second semester. The results of mixed-effects modeling demonstrated significant changes in both phrasal and clausal complexity and syntactic variety at the phrasal level, evidencing growth towards a more phrasal complex academic style. Task type also had a significant impact on these measures; higher values were generally found in summary writing responses. The results are discussed in light of previous literature as well as the characteristics of the source texts, and theoretical and methodological implications for writing complexity research are offered.