This volume brings social science research infrastructures to the foreground and provides a conceptual framework for understanding them. Key common denominators are that they provide public good resources for research, and that they are established to support research for the long-term. Research infrastructures are embedded in research practices and communities, at national and international levels. They enhance the efficiency of the research process as well as fundamental aspects of the scientific method, for example, comparability, replication, and diffusion of knowledge and information. The contributions within this book demonstrate that research infrastructures are triggering a major paradigm shift in the social sciences, with profound effects on the nature of knowledge production within and across disciplines. Indeed, they are in large part responsible for an invisible revolution that is affecting research and researchers in fundamental ways. The focus of this book is on charting and clarifying their functions and their impact with the goal of improving our understanding of their underlying mechanisms, their challenges, and their immense potential for advancing science.