Renowned researchers have contributed to this publication covering philosophical roots, types and standards of evaluation and impact research. It also discusses tools and methods for evaluating education and training systems and reforms are discussed. Competence measurement as well as design and selection of key competences in an international context are also addressed. This publication is part of the background report to Cedefop's third research report, dedicated to evaluation and impact of education and training. The other volumes address the Impact of education and training and the Evaluation of systems and programmes. The third research report is complemented by a synthesis report which provides a comprehensive review of types and results of evaluation and impact research in Europe and beyond. The series of Cedefop reports on vocational education and training research have been published since 1998. They take into account the wider context in which vocational education and training is embedded and discuss the implications for policy, practice and future research.