摘要:Abstract This study scrutinized the effect of task complexity on cognitive processes of L2 writers with respect to L2 writing expertise, speed of lexical retrieval, L1, and text quality. Sixty TEFL students with different writing expertise completed a computerized Written Productive Translation, as well as three L1 and L2 argumentative writing tasks, manipulated in regard to resource-dispersing dimensions followed-up by retrospective questionnaires. The texts were analysed in terms of accuracy, fluency, and syntactic complexity. Running MANOVA indicated that task complexity had no effect on fluency, accuracy, and syntactic complexity. However, the speed of retrieval was remarkably affected by writer's expertise. Moreover, there was no difference between L2 and L1 writing processes. The upshot essentially substantiated Cummins (1978) Interdependence Hypothesis, and Kellogg's (1990) Overload hypothesis while laying a great stress on the rate of lexical retrieval for improvement of writing expertise.