Teacher knowledge is currently explored in three major research paradigms. This paper reviews how teaching and personal educational knowledge are related in these three paradigms, namely: the evidence paradigm, the life history paradigm and the practice theory paradigm. The paradigms can be linked through their demand to elaborate knowledge transformation conceptually. This paper introduces some perspectives for conceptual elaboration of knowledge transformation: a post-critical epistemology is used to distinguish two modes of knowledge: practical educational knowledge which provides orientations for teaching, and personal educational knowledge which provides orientations for reflection on teaching. These two modes of knowledge are consequently linked through the concept of technologies of the self as introduced in the epistemology of Foucault, which provides perspectives to relate practical with personal educational knowledge and comprehend how teachers transform their knowledge to adapt and develop their teaching with respect to specific teaching contexts.