Sustainable lesson study and paradidactic infrastructure: the case of Denmark

Most widely published books and papers on lesson study emphasise that a main attraction of this format is that it enables teachers to build and maintain a shared knowledge base for the teaching profession. This, however, clearly requires that lesson study is established as more than an occasional experiment, which is new to most teachers involved and involves only exceptional teachers. Therefore, research on lesson study increasingly focuses on the question of sustainability of the format as a practice-based form of professional development. We present and expand the recent theoretical idea of paradidactic infrastructure and analyse sustainability from the institutional perspective of the Anthropological Theory of the Didactic and especially based on the idea of paradidactic infrastructure. Our data come from the Danish context where lesson study in mathematics has been experimented with for more than 10 years, first by individual researchers and now, increasingly driven by institutions, such as schools or municipalities.