In exchange for the autonomy they have been granted, schools are required to evaluate the quality of the education they provide. Self-evaluation initiatives are a frequently chosen method. The present article reveals the underlying processes which have an impact on the results of such self-evaluations. It is based on research which demonstrates that self-evaluation processes that strongly comply with certain policy-related principles have a greater chance of success than processes in which this is not the case or only to a lesser degree. These principles are presented here in such a way that they can serve as a series of guidelines for the design and evaluation of self-evaluation processes.