For the past two decades, evaluation of development assistance has relied on criteria of the OECD Development Assistance Committee (DAC) to assess the merit of development interventions in a structured and comparable way. In thousands of evaluations each year, evaluators thus assess the relevance, effectiveness, efficiency, impact and sustainability of projects and programs. Despite the near universal application of the DAC criteria, research on their use and usefulness remains scant. Existing guidance and evaluation research particularly ignores the question of how to assess the relevance of development interventions. This study seeks to fill this gap.