The third wave of Human Computer Interaction (HCI) involves more ubiquitous and embedded forms of computing. Making these useful, usable and even delightful for people needs design research. The more technologies become enmeshed in our lives and the more dependent upon them we become, the more essential it is that they are simple for everyone to use and they do not let us down in those annoying ways we have become used to tolerating. Embedding computing into more and more of the objects and environments we interact with makes them less visible but more ubiquitous, making their usability essential but challenging at the same time. Design research is a mechanism which can help researchers, programmers and designers to understand how to create better twenty-first century computing systems and environments. This chapter discusses how design research can contribute to allowing third wave HCI to benefit the lives of all citizens rather than frustrate them.