This paper aims to specify conditions that seem fruitful for enacting change in schools. It addresses a project involving teachers from lower secondary and primary schools. The project aims to develop formative assessment within science inquiry-based teaching methods. The elements underpinning this project are described. The effects on teacher conceptions and practices are shown. Data results from an analysis of the project material and of focus groups with the teachers involved. The methodology is based on the activity theory framework. The results are aligned with other research that showed how fruitful it is to involve teachers within cooperative settings where they can reflect about specific professional questions and tackle complex problems with other colleagues, researchers and teacher educators from university.
