I agree that a case study is a suitable qualitative design for your topic, especially since it allows you to explore exchange activities within a real context like HUFLIT. ...
I agree that a case study is a suitable qualitative design for your topic, especially since it allows you to explore exchange activities within a real context like HUFLIT. Your example of focusing on a small group and using interviews and observations is very clear and practical. One suggestion is that you could also include student journals or reflection logs to capture changes in speaking confidence over time. This might provide richer data and show development more clearly. Overall, your design is well-justified and fits your research aims.