This section presents a brief discussion of IEG 's objectives-based evaluation approach. It offers the advantages of using this approach and provides the definitions of IEG 's performance rating criteria: outcome, sustainability, institutional development impact, and bank and borrower performance.

The World Bank uses an objectives-based approach to evaluation. This approach to evaluating development work has three major advantages:

• it enhances accountability by focusing attention on the extent to which objectives agreed to with the Bank's Board of Executive Directors have in fact been achieved;it promotes efficiency by relating the use of scarce resources to the accomplishment of specific outcomes; and
• it allows comparisons by applying a common metric across the wide array of sectors and countries for which the Bank provides financing.

IEG evaluates development interventions by assessing how their results stack up against their own stated objectives. At the project level, this methodology focuses on outcomes, sustainability, and institutional development impact of Bank operations. This evaluation approach has been extended to country, corporate, sector, thematic and global policy evaluations by making suitable adjustments to the criteria. OutcomeIEG evaluates outcomes by considering three factors:

• the relevance of the intervention's objectives in relation to country needs and institutional priorities;efficacy, i.e. the extent to which the developmental objectives have been (or are expected to be) achieved; and
• efficiency, i.e. the extent to which the objectives have been (or are expected to be) achieved without using more resources than necessary.

SustainabilityIEG's sustainability measure assesses the resilience to risk of net benefits flows over time by answering these questions: At the time of evaluation, what is the resilience to risks of future net benefits flows? How sensitive is the project to changes in the operating environment? Will the project continue to produce net benefits, as long as intended, or even longer? How well will the project weather shocks and changing circumstances? Sustainability reflects the resiliency to risks of a project as measured by the likelihood that its estimated net benefits will be maintained or exceeded over the project's intended useful life. Institutional Development ImpactThe institutional development impact measure evaluates the extent to which a project improves the ability of a country or region to make more efficient, equitable and sustainable use of its human, financial, and natural resources. IEG evaluates each project's success in fostering such changes. Bank and Borrower Performance

IEG's assessments of Bank and Borrower Performance focus on how good a job each partner has done during the different stages of the project cycle, i.e, project identification, preparation, appraisal and implementation. Bank performance is judged based on the extent to which services provided by the Bank ensured quality at entry and supported implementation through appropriate supervision (including ensuring adequate transition arrangements for regular operation of the project). Borrower performance evaluates the extent to which the borrower assumed ownership and responsibility to ensure quality of preparation and implementation, and complied with covenants and agreements, towards the achievement of development objectives and sustainability.