International audienceThe crucial role of the quality of classroom interaction is highlighted in many qualitative studies, especially in connection with research on fostering (language learners') conceptual understanding of mathematics. But what exactly characterizes quality of classroom interaction? We want to address this question with the aim of proposing different criteria and disentangle the complex phenomenon into the talk-related, discursive, conceptual and lexical dimensions of the interaction. Therefore, we give an overview on related qualitative studies and deduce categories for the quality of classroom interaction for both, teachers' measures for activating students and for students' participation. This disentangling can establish a theoretical foundation for future research, as it provides directions for an operationalization for quantitative video-ratings