This thesis focuses on how principals’ practices in improvement work are formed and how these practices affect principals’ possibilities to work with planned change. The study takes its departure from ten Upper Secondary School principals’ improvement work concerning enterprise education. The study has an action research approach and was carried out between June 2009 and September 2010. The aim of the study is to generate knowledge about principals’ practices in improvement work and of action research as a strategy for principals in planned change in relation to these practices.               

The theoretical framework is based on practice theories (Kemmis & Grootenboer, 2008; Schatzki, 2002). According to these theories, a practice is formed in a project that shows what the practice is aiming for by practitioners’ sayings, doings and relatings. Furthermore, Kemmis and Grootenboer (2008) claim that practices are shaped by arrangements outside the practitioners; cultural-discursive, material-economic and social-political arrangements.                                                                       

Findings show that what becomes meaningful for principals to engage in is not formed only by the aim of the planned improvement work, but also by already existing practices competing for space and by arrangements constraining principals’ possibilities to work with planned change. Many practices and projects were competing on the arena where the improvement work was planned to proceed. Some of the projects, ‘leading the improvement work’, ‘understanding what enterprise education is about’ and ‘making changes for enterprise education’ promoted the planned change. Others, projects like ‘organizing the daily work’, ‘avoiding dispute with teachers’ and ‘pretending to succeed’, constrained the planned change. Furthermore, cultural-discursive arrangements like abstract ideas of what the principals were supposed to create conditions for, as well as social-political arrangements like asymmetric relationships between the principals, and expectations from the local school board for quick solutions, enabled practices that constrained the planned change. Practices and arrangements like those in the study made it difficult for the principals to engage in action research as a strategy for change.                                                                                                                                         

Based on the results, principals’ possibilities to work with planned change are discussed in relation to the matter of context, dialogue as an improvement strategy, the aim for the improvement work and demands for quick solutions. 

The thesis contributes with knowledge about planned change and it contributes to the discussion about what kind of arrangements could support principals to initiate and lead school improvement. It also shows the importance of practice analyses in school improvement processes.