Impact of generative AI chatbots and interaction modes on the speaking proficiency of adolescent EFL learners

Speaking proficiency in a second or foreign language (L2) is crucial in language learning; however, it poses challenges and induces anxiety in learners. Recent advancements in generative artificial intelligence (GAI) and natural language processing address these challenges using GAI chatbots. However, further empirical research is required to validate their efficacy in enhancing L2 speaking proficiency. This study investigated the impact of GAI chatbots on the speaking proficiency of 88 eighth-grade Taiwanese English as Foreign Language (EFL) learners participating in a summer program. The participants interacted with CoolE Bot, a GAI chatbot, for 45 min each day, and were divided into three groups: (1) the Bot-S group, who interacted with CoolE Bot via speech; (2) the Bot-SW group, with flexible usage of speech and text; and (3) the non-Bot group, who interacted with teachers and peers in conventional English classes. Quantitative (English-speaking) and qualitative (semi-structured interviews) data were collected and analyzed, revealing that CoolE Bot significantly enhanced the speaking proficiency of EFL learners. Based on participant interviews, the highly interactive and versatile conversational capabilities of CoolE Bot maintained a coherent dialogue flow and handled intricate inquiries. Generating contextually relevant responses based on extended interactions facilitated authentic communication, thus improving speaking proficiency. Incorporating multiple characters, human-like personalities, and synthesized voices sustained the motivation of the learners and engaged them in English-speaking practices. Both speech-only and speech-text interaction modes enhanced speaking proficiency in human-GAI chatbot interaction. Integrating GAI technology with the flexibility of EFL learners to choose interaction modes or utilize supportive functions facilitated cognitive offloading, thereby increasing their English speaking proficiency.