Jos Vaessen (PhD) is evaluation adviser at the Independent Evaluation Group of the World Bank (since 2016) and an evaluation capacity development expert at the Global Evaluation Initiative (GEI). He has been working in evaluation research since 1998, first as an academic evaluation consultant and later as a lead evaluator. He has conducted and led evaluations for multilateral and bilateral development organizations in a range of policy fields such as agriculture, environment, science, education, health and others. Jos currently leads the GEI’s professional development and knowledge program. As part of his duties, he is also regularly involved in training activities as well as peer review and advisory activities within and outside the World Bank Group. Jos has authored several internationally peer-reviewed publications, including three books. His most recent publication is titled Evaluation of International Development Interventions: An Overview of Approaches and Methods.