An essential responsibility of every nonprofit organization is to assess the impact of its actions and to learn from its previous work to better serve the community in the future. Evaluation demonstrates a nonprofit organization's fulfillment of its mission through a systematic, verifiable approach to measuring effectiveness and identifying areas for improvement. An organizational culture of evaluation drives continuous improvement, enhancing performance and efficiency. Evaluation results should serve as a key determinant to strategic decision-making and planning, enabling an organization to best utilize its resources in areas with the greatest returns. Evaluation results, and the associated organizational learning, are important for fulfilling organizational purpose, establishing accountability with stakeholders, and for encouraging continued investment of resources by funders and supporters.