This chapter discusses the choices that one teacher, Sharon Fargason, makes while attending and responding to student thinking. In particular, it identifies her tacit choice between focusing more 'widely' on student's epistemological framing and more 'narrowly' on specific conceptual substance. Prior analyses have focused on when and how teachers direct their attention to the substance of student thinking, arguing that it is context-sensitive and influenced by many factors, including the teacher's long- and short-term instructional goals, content knowledge, epistemologies, local classroom dynamics, and institutional expectations and time constraints. Redish proposed the construct of epistemological framing to connect research on epistemological resources with research on framing. Teaching involves many choices, mostly tacit, that influence what the teacher notices and what aspects of student's thinking he or she pursues. If learning science means becoming familiar with it as kind of epistemic activity, then teaching science means, in part, helping students develop a sense of the epistemic norms and values of the discipline.