Restorative justice - as an innovative approach to crime and criminal justice - has been growing constantly over the past twenty years. Its practices seem to hold great promise for victims, offenders, local communities, and the criminal justice system. Research has been set up in many countries to assess and explore restorative justice processes and outcomes. In spite of many program evaluations showing positive results, risks have been identified as well. Moreover, critics have depicted research in the field of restorative justice as 'a mile wide but only an inch deep.' In response to the criticism, this book takes up the challenge to examine restorative justice research as it is undertaken in nine European countries during last twenty years. The book provides an overview of empirical research on victim-offender mediation and conferencing. The research deals with a variety of topics and many of the findings have never been published in English before. The book presents research approaches and results in various countries in order to enhance comparison and to allow further reflection on the possibilities and limits of undertaking European research in this field. This work is the result of the EU funded COST (European Cooperation in Science and Technology) Action A21 on 'Restorative Justice Developments in Europe,' and includes contributions by researchers with broad experience in the restorative justice field, supported by policy makers and practitioners.