'Large reforms' have been set in motion in many educational systems at the beginning of the 21st century. They are on the political agendas, not only of industrial countries in the western world. The intended general goal of the activities is to increase the performance of the respective school system, being made perceptible by the achievement of the respective student body. This ZfE-Sonderheft is providing a platform to discuss critically by using first empirical data the kind of effects the reforms are having, including those impacts that were unintended. The contributions reflect reforms in the USA, Great Britain, Northern Europe and Germany. Die Beiträge im ZfE-Sonderheft bieten eine kritische Diskussion aktueller Entwicklungen, basierend auf empirischen Untersuchungen über die Effekte der Reformen - erwünschte ebenso wie unerwünschte. Betrachtet werden Reformen in den USA, Großbritannien, nordeuropäischen Ländern und Deutschland.
