The relationship between lexical use and L2 writing quality: A case of two genres

Abstract Extensive research has been done to explore how lexical use could predict the rated quality of L2 writing. However, the degree to which the rated quality is influenced by lexical use in different genres of L2 essays is relatively unexplored. This study tested the effect of lexical use on the rated quality of L2 argumentative and expository essays. Three natural language processing tools (i.e., the Lexical Complexity Analyzer, D_Tools, and TAALES) were employed to obtain the index of lexical density, diversity, and sophistication. Results suggested that the rated quality of both genres of L2 essays was not significantly predicted by lexical density and lexical diversity but was predicted by different indices of lexical sophistication. The striking difference in the prediction of lexical sophistication on the writing quality for both genres bears on academic word use. The observed pattern on lexical use in L2 writing across the two genres attested to the assumption that genre embodies socially constructed linguistic practices whereby L2 learners use various linguistic forms to achieve communicative goals.