Several empirical studies have shown that L2 interaction promotes L2 learning. However, recent research has also shown that individual differences, such as working memory capacity, can impact the benefits of feedback. Working memory capacity is argued to be responsible for storing and processing incoming input and has been measured with a number of elicitation methods such as phonological short-term memory (digit and non-word span), reading span, and operation span. We argue that the time is right to replicate studies that unify the research areas of working memory capacity and L2 learning.
We selected and analyzed two recent studies (Révész 2012 and Goo 2012) that investigated how working memory capacity mediates effectiveness of feedback (recasts and metalinguistic feedback). In Goo’s study, it mediates the effects of recasts, but not of metalinguistic feedback; in Révész, it depends on the type of working memory test. We think these two studies represent recent directions in the field, address the important construct of working memory capacity whose measurements show potential methodological issues, and provide detailed descriptions of all aspects of the studies to facilitate replication. In the attempt to generalize findings, we emphasize the importance of replication in a number of different areas including grammatical complexity of the target structure, the nature of the working memory tests, modes of delivery, and the possibility to gather information about the thought processes through stimulated recalls.