Researchers in the science education community make extensive use of cognitive clinical interviews as windows into student knowledge and thinking. Despite our familiarity with the interviews, there has been very limited research addressing the ways that students understand these interactions. In this work, we examine students' behaviors and speech patterns in a set of clinical interviews about chemistry for evidence of their tacit understandings and underlying expectations about the activity in which they are engaged. We draw on the construct of "framing" from anthropology and sociolinguistics and identify clusters of behaviors that indicate that students may alternatively frame the interview as "inquiry," an "oral examination," or an "expert interview." We present two examples of students shifting between frames during the course of individual interviews. By examining the surrounding interaction, we identify both conceptual and epistemological interviewer cues that facilitate and constrain frame shifts. We discuss the implications of dynamic student framing, that is identifiable in student behaviors and discourse, for researchers who use clinical interviews to map student's intuitive science knowledge.