In May 2012, the World Health Assembly endorsed the World Health Organization (WHO) evaluation policy, emphasizing the fact that evaluation is an essential part of the work of the Organization. The evaluation policy intended to bring to fore a few important principles of WHO's work: further accountability, systematic provision of oversight of performance, and ensuring that the Organization continues to learn from its experiences. The endorsement of the policy was followed by important and immediate actions, most notably the publication of the WHO Evaluation Practice Handbook and the establishment of the WHO Evaluation Office.