ABSTRACT
This chapter describes an evolving new class of collaborative research methods called multitiered design experiments. After a brief introduction to the general concept of such studies, the chapter is divided into four sections. The first compares and contrasts the origins of the term design research in cognitive science versus mathematics and science education. The second describes how design research requires a reconceptualization of many traditional notions about researchers’ roles, subjects, relevant theories, and the nature of results. The third gives a concrete example of a multitiered design experiment that investigated the development of knowledge for three interacting types of subjectsstudents, teachers, and experts who know about the kinds of mathematical knowledge needed for success beyond school. The fourth describes two common design flaws in design experiments; then, several quality assurance principles are described which should apply to the ways that such studies are conducted.
