This article analyses microprocesses within an intervention project at a Danish upper secondary school (the AK project, AK is an acronym for the school), which aims to develop teachers" understanding of student notes and subsequently their way of dealing with them in their teaching practice. The focus in the study is how the teachers formulate and reformulate the project ideas. These formulations and reformulations are assumed to be caused by the teachers" experience of contradictions between new ideas and established practices, attempts to make sense of the new ideas, resistance, misunderstandings etc.