The purpose of the evaluation phase is to make an “assessment, as systematic and objective as possible, of an ongoing or completed project, programme or policy, its design, implementation and results. The aim is to determine the relevance and fulfillment of objectives, developmental efficiency, effectiveness, impact and sustainability. An evaluation should provide information that is credible and useful, enabling the incorporation of lessons learned into the decision-making process of both recipients and donors”. (Source: OECD/DAC, 1998: Review of the DAC Principles for Evaluation of Development Assistance.).

An evaluation can be done during implementation (“mid-term”), at its end (“final evaluation”) or afterwards (“ex-post evaluation”), either to help steer the project or to draw lessons for future projects and programming.