This chapter provides an introduction to design research. It outlines the history of the various ways in which scholars tried to resolve problems and how the solutions led to variations of design research in the specific contexts in which the scholars operated. The chapter summarizes five key characteristics of design research. The first characteristic is that its purpose is to develop theories about learning and the means that are designed to support that learning. The second characteristic of design research is its interventionist nature. The third characteristic is that design research has prospective and reflective components that need not be separated by a trial or so-called teaching experiment. The fourth characteristic is the cyclic nature of design research: Invention and revision form an iterative process. The fifth characteristic of design research is that the theory under development has to do real work.