In 1973, Landauer and Streeter (1973) introduced N-metric. N refers to the number of words that can be created by changing a single letter of a target word. One of the first studies in this field was conducted by Coltheart, Davelaaar, Jonasson, and Besner (Coltheart, Davelaar, Jonasson, & Besner, 1977), who reported that classification of high-N nonwords is slower than that of low-N nonwords. Since 1973, few studies have actually measured neighborhood effect on foreign language learners' lexical retention. The aim of this book is to move beyond first language and apply current lexical...