A Corpus-Based Study: EFL College Students Using COCA to Improve Lexical Usage in Written Production

Corpus linguistics has attracted growing interest from linguistics, researchers, and language educators. This area is potential for studies in linguistics as well as improvement in language learning. This study aims at investigating how a corpus-based website named https://www.english-corpora.org/coca/ - or COCA - helps improve students' lexical usage in written production. Participants were EFL students from a university using COCA over two months for revising vocabulary in their writing assignments. Data included the measure of textual lexical diversity (MTLD) of the participants' revised assignments and their reflections/reviews on using COCA. Results reveal some positive changes in MTLD values, while participants' feedbacks suggest COCA is useful for gaining knowledge about lexis, and improving the use of collocations, synonyms as well as high-lexis despite some challenges of unfamiliar interface and overwhelming contents. The study implies the feasibility of applying corpora provided that there are sufficient facilities and careful training for learners.