Planning a mixed methods research project can be a daunting task. This chapter outlines two key features of conducting mixed methods research, undertaking a systematic process and using mixed methods terminology. It explains how to create an appropriate mixed methods central research question, including all the practical factors that need to be taken into consideration. The chapter discusses mixed methods research as: the systematic and rigorous bringing together of qualitative and quantitative research methods and data into a coherent whole, where this whole is greater than the sum of its individual component parts, in order to answer a central research question. The notion of working systematically may seem quite overwhelming when beginning to think about undertaking a mixed methods research project because of all the decisions that need to be made. A central research question is ‘the overarching question that defines the scope, scale and conduct of a research project’.