University rankings are a relatively new phenomenon in higher education. Although quite an established practice in the U. S., it is only within the last decade that attempts to analyse university performance have spread to the rest of the world, and that we also have seen new global rankings appear-rankings attempting to measure university performance beyond national borders. No wonder that this trend is accompanied by a growing interest in studying rankings throughout the world. This book is written as part of the effort to better understand rankings and their effects on higher education.A serious approach towards university rankings implies that rankings should be analysed properly, including the methods used and the indicators chosen, and investigate the objectives claimed. If university rankings are considered as consumer information then everyone should have an interest in basing such guidance on valid and reliable data and methodology. A serious analysis should also discuss the wider implications of rankings as an emerging phenomenon in higher education.Consequently, the contributions to this book investigate and analyse how different rankings work, how they reach their conclusions, and on what data and methodology they are built. Furthermore it provides a critical reflection about the impact of rankings on higher education, how and in what way rankings influence policy-making, the structure of the sector, or the internal life of the sector.