This issue of Educational Technology describes advances in design-based research (DBR), an important addition to the methodological repertoire of educational scholars, practitioners, and policy-makers. These articles portray why DBR is a useful complement to traditional research strategies such as laboratory studies and randomized clinical trials. The case studies they provide also illustrate why DBR is most effectively conducted through partnerships of researchers with educators immersed in the crucible of practice. However, DBR is difficult to do well, and this issue delineates the considerable challenges of using this methodology to develop effective, scalable, and sustainable educational innovations