Mixed Methods Research (MMR), as a pluralistic research approach, integrates a wide range of research perspectives, approaches and methods and serves as a pragmatic research toolkit for learning scientists to explore and understand learning phenomena prior to or in parallel with intervening in or designing any learning situation with the end-goal to further inform theory and practice. This chapter highlights the contribution of MMR in the Learning Sciences as a stand-alone or integrated research approach. The main contribution of MMR lies in (a) informing theory and practice based on pluralistic and multi-layered evidence-based claims and (b) informing “design for practice” (e.g., Design-based Research decisions).