Effects of task complexity on the learning of genre specific rhetorical moves and linguistic forms: The case of contrast and argumentative essays

This study investigates whether task complexity improves L2 English learners' ability to write contrast and argumentative essays as measured by the use of rhetorical moves and linguistic forms characteristic of these essays. The participants were 62 students in an undergraduate-level composition class in a private university in the U.S. The study involved a first phase that targeted contrast writing and a second phase that targeted argumentative writing. In both phases, students were assigned randomly to a simple or complex task group and wrote an essay in dyads. In terms of rhetorical moves, the complex task group outperformed the simple task group in the immediate and delayed post-test of contrast essays. For argumentative essays, this superiority of the complex group was only found in the immediate post-test. As per linguistic forms, the complex task group outperformed the simple task group in the immediate and delayed post-test of both contrast and argumentative essays.