This chapter describes that people cannot disentangle knowledge analysis from interaction analysis. They are both part and parcel of the success and navigation of cognitive clinical interviews used for research purposes. People describes the various types of turns that interviews use to traverse students' conceptual ecologies by defining those turns in relation to the students' previous and subsequent utterances. If knowledge and interaction are inherently intertwined in cognitive clinical interviews, then interviewers must be prepared to recognize different types of failures, maintain constant awareness of both knowledge and interactional cues from students, and develop a set of strategies or turns that they can flexibly use to navigate failures. Much of science education research is concerned with understanding children's prior knowledge of the natural world. In much of people own work, they adopt a perspective on scientific cognition that has been described by such terms as conceptual ecology, knowledge in pieces, and a systems perspective.