Combining AI and Corpus Technology in Language Teaching: Professional Development and Knowledge Co-Construction Using the CoI Framework

As established technologies (e.g., corpus technology) and emerging ones (e.g., generative AI) reshape language education, teachers need clear, evidence-based approaches to integrate both into practice. This mixed-methods study examined how over 150 language teachers co-developed AI-empowered TPACK for corpus technology (AI-TPACK-CT) during online professional development. The program was designed using design-based learning and guided by the Community of Inquiry (CoI) framework, which views effective online learning through learners’ social and cognitive engagement. We analyzed discussion posts, lesson plans, and interviews to trace teacher engagement, knowledge building, and learning outcomes. To understand participation patterns at scale, we conducted social network analysis (SNA) to map interaction structures, and then selected participants for deeper investigation. We conducted case studies of one central participant and two peripheral participants to explore how these teachers’ knowledge and design work evolved. CoI-based quantitative results indicated high social and cognitive presence, suggesting an environment conducive to shared inquiry and knowledge building. Qualitative analyses of lesson plans and interviews further showed that teachers’ TPACK development followed different trajectories depending on engagement level and professional experience. Overall, the findings link teachers’ CoI interaction patterns, underlying cognitive processes, and observable design outcomes, extending CoI operationalization beyond postings alone. The study contributes (a) an empirically grounded account of co-developing AI-TPACK-CT through design-based learning where corpus knowledge is playing a key role fostered through AI and pedagogy; (b) evidence on how CoI and SNA relate to TPACK growth; and (c) practical implications for scalable, evidence-centered teacher learning that supports collaborative inquiry, reflective practice, and data-informed integration of AI and corpus technology in language teacher professional development.