  A student's epistemological stance (be it knowledge as memorized information,
knowledge from authority, or knowledge as invented stuff) may constrain that
student from reasoning in productive ways while also shaping the inferences a
researcher can make about how that student reasons about a particular
phenomenon. We discuss both cases in the context of an individual student
interview on charge flow in wires. In the first part of the interview, her
focus on memorized knowledge prevents the researcher from learning about her
detailed reasoning about current. In the second part of the interview, her
focus on constructed knowledge provides the researcher with a picture of her
reasoning about the physical mechanisms of charge flow.
