Evaluation serves as an input to provide decision-makers with knowledge and evidence about performance and good practices. Based on credible, objective, valid evidence-based information, evaluation can be a powerful tool that can make programmes and projects, and therefore UNODC, more effective and efficient.
Evaluation assures accountability by reporting on UNODC activities to the Governing Bodies. By providing objective and up to date evidence of what UNODC has achieved and what impact has been produced using the resources provided, evaluation also aims at accounting for the use of resources and for the results produced to all UNODC stakeholders, including staff and management, donors, Member States, target groups and implementing partners.
The approach to evaluation adopted by UNODC is to encourage the wider participation and consultation of internal and external stakeholders during the planning, design and conduct of evaluations and the follow-up on them, while maintaining strict impartiality and independence in framing conclusions and recommendations.
The present Evaluation Handbook aims to support UNODC in mainstreaming evaluation processes, learning and accountability into UNODC project and programme delivery.
Furthermore this Evaluation Handbook responds to Member States' demand for a strengthened evaluation function and culture  within UNODC and I hope that the publication of this Handbook will help us and our partners to better respond to UNODC's needs and demands.
The present Handbook, launched in 2012, is based on the 2008 Evaluation Handbook and collective experiences of staff working in the Independent Evaluation Unit.
The Independent Evaluation Unit expresses its deep appreciation to the colleagues from the United Nations Development Programme (UNDP) for sharing with us the UNDP Handbook on Planning, Monitoring and Evaluating for Development Results which was a great source of inspiration for the present Handbook.
Katharina Kayser, Chief, Independent Evaluation Unit, UNODC
 Commission on Crime Prevention and Criminal Justice (CCPCJ) resolution of December 2009 (CCPJ E/CN.15/2009/L.15) and Commission on Narcotic Drugs (CND) resolution of January 2010 (E/CN.7/2010/13-E/CN.15/2010/13).