This paper explores themes emerging in classroom videotapes of a middle years science classroom from a case study of student identity and agency using discursive psychology. The research was conducted in response to the widespread problem of student disengagement with science in the middle years of schooling and related calls for research into the way in which students develop identities in and through school science. The purpose of the paper is two fold: firstly, drawing on Harre’s model of Identity Projects to present findings showing one student’s reflexive positioning in dialectic relation to local practice; and secondly to discuss the implications for research and practice in science education. In particular, the paper supports work by Davies (2008) and Zembylas (2005) by questioning science classroom practice in which student expression of interest and desire is neither published nor conventionalised. References Davies, B. (2008). Re-thinking 'Behavior' in Terms of Positioning and the Ethics of Responsibility. In A. M. Phelan and J. Sumsion (Eds.) Provoking Absences: Critical Readings in Teacher Education, Rotterdam: Sense Publishers: 173-186. Zembylas, M. (2005). Three perspectives on linking the cognitive and the emotional in science learning: Conceptual Change, Socio-Constructivism and Post structuralism. Studies in Science Education 41(1/2): 91-114.