This article describes how school leadership in a vocational secondary school used a research circle to establish collegial learning. The goal was to develop the teaching skills of teachers and, as a result, also develop the ability of students to assess their own knowledge and understanding, as well as their capacity to learn. The results are based on data from a qualitative case study in accordance with an action research tradition. The article reflects a contemporary education policy debate on the role of teachers in relation to students’ poorer study results. The teachers that participated developed and tested subject-specific self-assessment matrices in mini-research projects. Many of the students seemed to benefit little from using these matrices. Possible explanations may be that the students felt no motivation neither to improve their knowledge and skills nor to raise their grades. There did, however, seem to be differences between theoretical and vocational subjects. The research circle served to develop collegial learning among the participants and also played a role in the establishment of a school development group.