Design Research as a Means for Building a Knowledge Base for Teachers and Teaching in Mathematics Education

Building on the claim that teachers need to know how innovative instructional approaches work to be able to adapt them to their own classrooms, design research is presented as a research method that aims to offer exactly that kind of information. We elaborate design research that aims to develop a local instruction theory-a theory about the process by which students learn a given topic in mathematics and theories about the means of support for that learning process. We will illustrate this with the example of design research on a local instruction theory on addition and subtraction to 100. We further discuss design research that combines the 2 goals of teacher learning and student learning in 1 project as a special case of research on teacher learning. In closing, we briefly look into the relation between design research and teacher research.