Expounding on physics:: a phenomenographic study of physicists talking of their physics

Physicists and physics students have been studied with respect to the variation in the ways they expound on their topic of research and a physics problem, respectively. A phenomenographic approach has been employed; six fourth-year physics students and 10 teacher-researcher physicists at various stages of their careers have been interviewed. Four qualitatively distinct ways of expounding on physics have been identified, constituting an outcome space where there is a successive shift towards coherent structure and multiple referent domains. The interviewed person is characterized as expressing an 'object of knowledge', and the interviewer is characterized as a willing and active listener who is trying to make sense of it, constituting a 'knowledge object' out of the ideas expressed and personal experience. Pedagogical situations of analogous character to the interviewer-interviewee discussions are considered in the light of the analysis, focusing on the affordances for learning offered by the different forms of exposition.