The theme of this volume, complexity, accuracy and fluency (CAF) as dimensions of second language production, proficiency and development, represents a thriving area of research that addresses two general questions that are at the heart of many studies in second language acquisition and applied linguistics: What makes a second language (L2)…

The research project reported in this chapter consists of three studies in which syntactic complexity, lexical variation and fluency appear as dependent variables. The independent variables are task complexity and proficiency level, as the three studies investigate the effect of task complexity on the written and oral performance of L2 learners of…