The Complexity of Input and How It Contributes to Adult Second Language Acquisition

Previous research has explored the efficacy of different types of second language (L2) training in fostering adult L2 development (e.g., Norris & Ortega, 2000; Morgan-Short, Steinhauer, Sanz, & Ullman, 2012). However, relatively little attention has been paid to the type of input (e.g., simple or complex) provided during training, even though some literature supports the idea that simple input is more advantageous at initial stages of L2 development. The current study addressed this issue by exploring how the type of L2 input in implicit training conditions affects initial adult L2 development in terms of both overall learning and the type of knowledge developed. Participants were assigned to training conditions where they received either simple or complex input during L2 training and learned an artificial L2 in order to play a computerized board game. After training, participants completed a grammaticality judgment task (GJT) that assessed grammar rule knowledge and a comprehension task to assess L2 development. Participants also responded to subjective measures that were embedded in the GJT (Rebuschat &Williams, 2012). Results showed better overall development on both the GJT and the comprehension test when learners were provided with simple input. Participants who received complex input showed above chance performance only on test items that paralleled the structure of training items. When examining knowledge development (through source attributions), learners in the simple input condition evidenced more diverse types of knowledge (both explicit and implicit) than learners in the complex input condition. These results suggest that providing adult L2 learners with simple input leads to greater overall development at the initial stages of learning an L2.