See here our first video to introduce design research in education to a wider audience (students, PhD students, early career researchers):
This type of research has emerged one the one hand to improve the design of educational materials, tools, and curriculum, which often are developed without a proper research basis. This focus was especially prominent in some technical universities (Van de Akker et al., 2006). Apart from this research-based design, researchers were after practically useful design principles as generalized ideas how to design similar learning environments in other situations.
On the other hand, many educational and psychological researchers wanted to make their research practically more relevant, work in classrooms rather than laboratories (Brown, 1992). They had ideas how to improve education and worked with teachers to create settings in which they could realize and test these ideas by means of new design.
Brown, A. (1992). Design experiments: Theoretical and methodological challenges in creating complex interventions in classroom settings. Journal of the learning sciences, 2, 141-178.
Van den Akker, J., Gravemeijer, K. P. E., McKenney, S. & Nieveen, N. (Eds.) (2006). Educational design research. London: Routledge.