Hello, Seungpyo Choi. While retrieval practice using NotebookLM (RAG tool) is certainly an important learning weapon, it is not the main content of the course. The core is to provide a strategic pipeline that eliminates inefficient steps throughout the entire learning process—before class (preview), during class (note-taking), after class (review), exam period, right before exams, etc.—and maximizes time by utilizing AI as a 'learning system building tool.' Retrieval practice through NotebookLM is just one part of that pipeline. If the course content felt like it was only explaining 'throwing PDFs into NotebookLM,' it seems our core message delivery was insufficient. We will review and supplement the course flow and emphasis points with this feedback in mind. Thank you for your valuable feedback.