Why do some schools fail to improve even after taking knowledge-based improvement initiatives? In this article, we argue that some schools do not improve because their staff members have an individual learning belief. An individual learning approach to school improvement will disrupt development processes. Whereas, as we argue, a social learning understanding of school improvement based on the theory of Community of Practice and its application may provide schools with a theoretical understanding which enables successful implementation. The results of two major improvement projects in Norway illustrate how some schools fail to successfully implement improvement due to the voluntary nature of participation, the lack of situated activities in relation to the improvement objective, the low frequency of meetings and the absence of systematic leadership. Our advice to schools is to revisit their beliefs about and understanding of learning so they can manage change among staff and carefully monitor the situations we highlight as being critical to success.