“…Since the 1990s, many studies have been carried out on the effect of different task characteristics on L2 learners' performance (Skehan and Foster, 1999;Elder and Wigglesworth, 2003;Ellis, 2005Ellis, , 2008Philp et al, 2006;Rahimpour, 2008;Wang, 2008;Mehrang and Rahimpour, 2010;Dadashpour, 2011;Shafaei, 2012, Salimi et al, 2012Dadashpour, 2012a, 2012b). Fewer studies have been devoted to the investigation of the joint effects of pre-task planning time and task complexity.…”