Design-Based Implementation Research is the process of engaging "learning scientists, policy researchers, and practitioners in a model of collaborative, iterative, and systematic research and development" designed to address persistent problems of teaching and learning. Addressing persistent problems of teaching and learning requires attending not only to theories of learning but also to theories of implementation and organizational context. Furthermore, conceptualizations of learning, implementation, and organizational context have implications for the design of interventions and the methodologies used to answer questions like: "What works when, how, and for whom? How do we improve this reform strategy to make it more sustainable? What capacities does the system need to continue to improve?" The authors review four projects that reflect the principles of design-based implementation research (DBIR) in an effort to highlight a range of relevant theoretical and methodological perspectives and tools that can inform future work associated with DBIR. This Yearbook constitutes an important part of building DBIR as a field in that it brings together people engaged in similar work to reflect on similarities and differences in practices across projects. The cases analyzed in this chapter illustrate different, productive approaches to identifying, adapting, and developing theories and methods in an effort to support the development of common language, knowledge, practices, and tools that future researchers can use to engage in DBIR.