Studies in Second Language Acquisition, 2012, 34, 445–474. doi:10.1017/S0272263112000149 © Cambridge University Press 2012 445 CORRECTIVE FEEDBACK AND WORKING MEMORY CAPACITY IN INTERACTION-DRIVEN L2 LEARNING Jaemyung Goo Gwangju National University of Education The present study explores the relative efficacy of recasts over meta- linguistic feedback on the learning of the English that-trace filter and how working memory capacity (WMC) is related to the extent to which learners can benefit from recasts and metalinguistic feedback. Fifty- four Korean English as a foreign language (EFL) learners from six intact classes at a university formed two experimental groups (recasts and metalinguistic feedback) and one control group and carried out two first language (L1) working memory (WM) span tasks (reading span and operation span tasks). The two experimental groups partic- ipated in two information gap activities over two treatment sessions, during which they were required to ask questions involving the that- trace filter and received corrective feedback (either recasts or meta- linguistic feedback) on their erroneous utterances. Two dependent variable measures (a written production test and a grammaticality judgment test) were administered in each test session (pretest and immediate posttest). Results showed that recasts were as effective as metalinguistic feedback in facilitating the acquisition of the target construction. This may, to some extent, be attributable to the blocking of modified output opportunities specifically designed in this study to prevent modified output from playing a potential role as a confound. Also, individual differences in WMC significantly predicted, and thus mediated the effects of, recasts but not metalinguistic feedback, on I would like to thank Patrick Rebuschat and Ana Maria Nuevo for their helpful comments on an earlier (longer) version of this article. I also thank the anonymous SSLA reviewers for their valuable input and feedback, and the participants in the study for their time and cooperation. Any errors are, of course, my own. Correspondence concerning this article should be addressed to Jaemyung Goo, Department of English Education, Gwangju National University of Education, 55 Pilmundaero Buk-gu, Gwangju, 500-703, South Korea; e-mail: jg349@gnue.ac.kr.