Exploring the Impact of ChatGPT on Vocabulary Acquisition in EFL Learners: A Mixed-Methods Study on AI-Assisted Language Learning

This study explores the effectiveness of ChatGPT, an AI-powered language model, is in helping EFL learners improve their vocabulary. Over five weeks, 50 female university students participated in a mixed-methods study that included Vocabulary Knowledge Scale (VKS) pre- and post-tests, as well as semi-structured interviews. The quantitative results showed a statistically significant improvement in vocabulary knowledge after using ChatGPT. The percentage of words rated as "very familiar" more than doubled, while the percentage of unfamiliar words decreased noticeably. A paired samples t-test confirmed that these gains were statistically significant (p = 0.006). To analyze the qualitative data, the study used thematic analysis approach. Key themes emerged: increased student engagement, practical benefits of ChatGPT, and concerns about overreliance on the tool. Students appreciated the quick responses and helpful examples, but also noted that some information was inaccurate or overwhelming. Overall, the findings suggest that ChatGPT can be a valuable tool for vocabulary learning, offering immediate support and contextual understanding. However, its limitations highlight the need for critical thinking and teacher guidance. This study adds to the growing research on AI in language education and provides practical insights into how tools like ChatGPT can be used effectively and responsibly in EFL classrooms.