The traditional role of educational research and theory for the mathematical teaching practice has been increasingly and extensively questioned during the last decade. There is something wrong with the usual understanding of the theory-practice-relation. Theories - be they as detailed and comprehensive as possible - cannot be transferred directly into the teacher's practice nor can they be applied immediately. Educational research cannot automatically improve teaching practice. Research results cannot be disseminated into teacher's practice simply in a strategy "from the top down". In one word, the old idea that the relationship of theory to practice is of a linear nature in a way that the theoretical results developed in research - if they are only adequately elaborated and made explicit - can be handed over to practice for immediate use will not longer work.
The CAUSE Research Group is supported in part by a member initiative grant from the American Statistical Association’s Section on Statistics and Data Science Education