Working Memory and Lexical Knowledge in L2 Argumentative Writing


The current research explores the relationship between L2 lexical knowledge and working memory on the written performance of argumentative writing by Chinese learners of English as a foreign language (EFL). There are two independent variables and one dependent variable in this study: L2 lexical knowledge consists of productive vocabulary knowledge, vocabulary size, and depth of vocabulary knowledge; working memory as indexed by the operation span task; and written performance in two argumentative tasks (indexed by accuracy, fluency and complexity). The results show that (a) productive vocabulary knowledge has a significant effect on fluency and accuracy but no effect on complexity of the written language production; (b) working memory exerts a considerable effect on fluency and syntactic complexity while it has no effect on accuracy and lexical complexity of the written language production; and (c) working memory affects productive vocabulary knowledge in that the learners with middle and low working memory capacity are more prone to be affected by productive vocabulary knowledge in the written production.