Language Learning ISSN 0023-8333 Learner-Generated Noticing of Written L2 Input: What Do Learners Notice and Why? Eun Sung Park Sogang University This study explored learners’ self-generated noticing of L2 input. It is motivated by previous research on input enhancement which suggested that learners are able to notice certain aspects of input on their own without any external means to direct their attention. Drawing on insights that learner-generated noticing is largely mediated by learner- internal factors, this study specifically traced the effects of learners’ first language (L1), and their current second language (L2) knowledge in generating noticing. Two L1 groups (Japanese and English) with no knowledge of the L2 (Korean) were exposed to written L2 input and probed for their noticing behavior under a “zero knowledge” condition, and a “some knowledge” condition (i.e., after they had been taught some L2 words). Results revealed that under the “zero knowledge” condition, both groups exhibited similar noticing patterns prompted by perceptual input properties. Under the “some knowledge” condition, however, the Japanese group seemed to have noticed more input items and processed them at a deeper level of understanding. Insights gleaned from the study are discussed with avenues for future research. Keywords input noticing; learner-generated noticing; L2 input processing; input en- hancement; learner-internal factors; L1 influence; L2 Korean This research was supported in part by the Spencer Foundation Dissertation Grant and the Sogang University Research Grant of 2009. I would like to thank ZhaoHong Han for her guidance and advice on my doctoral research, on which this article is based. I am also grateful to Andrea Revesz and Renee Jourdenais for reading the first draft of the article, and to the anonymous reviewers and Robert DeKeyser of Language Learning for their valuable comments and suggestions. Results obtained from one of the tasks (i.e., input marking task) were presented at the World Congress of Applied Linguistics (AILA) in Essen, Germany in August 2008, at the Second Language Research Forum (SLRF) held at the University of Hawaii in Manoa in October 2008, and at the Georgetown University Round Table on Languages and Linguistics (GURT) in March 2009. Correspondence concerning this article should be addressed to Eun Sung Park, Department of English Language and Literature, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742, South Korea. Internet: eunsungp@sogang.ac.kr Language Learning 61:1, March 2011, pp. 146–186 146 C  2010 Language Learning Research Club, University of Michigan DOI: 10.1111/j.1467-9922.2010.00589.x