Initially, Farming Systems Research took the farm as a starting point for an analysis of a broad range of issues linked to agricultural production. Soon afterwards, it was recognised that to understand farming, the scale of analysis needed to be broadened, to capture the interactions between farms and their natural, social and economic context. Topics of research now range from on‐ farm issues such as interactions between crop production and animal husbandry, to farmer pluriactivity, civic food networks, and how cultural landscapes are shaped by farming activities. Underlying this breadth of topics, three characteristics are identified as being constituent of Farming Systems Research: systems thinking, interdisciplinary and a participatory approach to research. In this chapter we discuss these three characteristics, and the challenges they pose in their  operationalization. Given these challenges, we discuss the reasons why Farming Systems Research is demanding, and we highlight that the core quality of a researcher is reflexivity, in designing, in implementing and in evaluating research.