Progress beyond the state of the art was achieved in conceptual modelling of knowledge transformation: The PEEK knowledge model is based on the assumption that teachers perform skilfully when classroom situations allow them to draw on their personal educational knowledge which orients situated attention in unforeseen events. However, some events are difficult to manage with previously established orientations sets because a situation comprises a set of characteristics that creates a novel context of teaching. This novel context creates experiences that teachers problematise in order to comprehend the characteristics of such a novel context, and transform their established knowledge in order to react to this context in the next episode of practice. The conceptual elaboration of professional knowledge transformation in PEEK points out that teachers manage situations in subsidiary and focal attention, and appraise situations based on these two forms of attention. Their appraisal leads to experiences of involved educational practice in class. Such experiences are taken up again in reflective educational practice, where teachers problematise their experiences in order to transform their knowledge for teaching – in Foucault terms their ontological homeland – and establish an elaborated set of orientations for teaching. This elaborated set of orientations enables teachers to attend to problems which they experienced in previous episodes of practice, and solve these problems in order to scaffold their learning in their classroom.