Examining lexical features and academic vocabulary use in adolescent L2 students’ text-based analytical essays

Having rich and complex vocabulary is a crucial component that contributes to the quality of writing for academic purposes. However, use of academic vocabulary can be challenging for adolescent L2 writers who are developing their academic language proficiency. Thus, understanding lexical needs of adolescent L2 students in composing academic essays is pivotal in supporting this population in their endeavor to become proficient academic writers. This study investigates the lexical features of adolescent L2 students' text-based analytical essays and analyzes the extent to which lexical density, lexical diversity, and lexical sophistication predict the quality of their writing. Computational tools Coh-Metrix and VocabProfiler were used to obtain quantitative measures of lexical density, diversity, and sophistication. The results of the study indicate that the essays (n = 70), on average, have (1) low lexical density, (2) more repetition of words indicating less diversity compared to grade-level estimates, and (3) a higher percentage of basic words and lower percentage of academic words. 44 % of the AWL words in the essays come from the source text and prompt. The results of multiple hierarchical regression indicate that the use of academic vocabulary is a predictor of writing quality. The study has important pedagogical implications for classroom practice at secondary school.