Teachers are the most important agents in shaping education for students and to bring change and innovation in educational practices. There is a lack of knowledge about how teachers learn and transfer their knowledge into practice in the classrooms. Teacher educators have repeatedly argued that classroom management is a critical pedagogical skill that teachers must master in order to maximize classroom interaction. This study aims to contribute to the understanding of how lower secondary school teachers learn and improve classroom interaction in the context of an educational intervention. Three aspects of classroom interaction are addressed: emotional support, classroom organization and instructional support. The sample contained 81 teachers from 14 Norwegian lower secondary schools reporting, through digital logs, on learning experiences with respect to classroom interaction. Moreover, they reported on the types of learning activities they undertook. Findings indicated that teachers' improvement in classroom interaction was, to a large extent, dependent on their own, or their colleagues' strong knowledge of classroom interaction. The results of the study add to our understanding of teachers' knowledge and skills within classroom interaction and how teachers can improve their knowledge, e.g., through reflection on situations in the classroom. Still, the authors suggest a stronger emphasis on the integration of research based knowledge and teacher learning strategies to support teachers to reach their full teaching potential.