Evaluation is a social science methodology for understanding the impacts of program investments and the key ingredients required tosustain effective programming over time. Evaluation has been increasingly applied to a diverse set of NPS program areas includinginterpretation and education (I&E), leadership development, 21st Century relevancy initiatives, national heritage areas, as well assupport of strategic planning at national parks. This session introduces various approaches to evaluation and panelists will offertheir perspectives on the opportunities, challenges, and lessons learned in using evaluation to improve program design and delivery.