We have both learnt a huge amount preparing and writing this book; from one another, from our reading, and from interviews with experts on individual methods. Systems mapping, and its related methods, concepts, and schools of thought, is a messy space. There are multitudes of definitions and overlapping ideas, subtle differences in approach, and sweeping assumptions. We had underestimated this before; we did not know the waters were shark-infested! This makes it an exciting space to work in, with many different fields and approaches within touching distance, but also a difficult one to navigate. This can be frustrating and off-putting, but the quality, usefulness, and fun of using many of the methods here keeps pulling us back. We truly believe all the methods in this book are valuable in many circumstances, and are, on the whole, under-used in research and practice. We feel better placed to navigate this space having written this book, we hope you do too having read it.