One of the main tools that we have for the study of student science conceptions is the clinical interview. Research on student understanding of natural phenomena has tended to understand interviews as tools for reading out a student's knowledge. In this paper, we argue for a shift in how we think about and analyze interview data. In particular, we argue that we must be aware that the interview itself is a dynamic process during which a sort of conceptual change occurs. We refer to these short time-scale changes that occur over a few minutes in an interview as conceptual dynamics. Our goal is to devise new frameworks and techniques for capturing the conceptual dynamics. To this end, we have devised a simple and neutral cognitive framework. In this paper, we describe this framework, and we show how it can be applied to understand interview data. We hope to show that the conceptual dynamics of interviews are complex, but that it nonetheless feasible to make them a focus of study.