This book aims to account for how project learning and adaptation occurs through Developmental Evaluation (DE), especially under conditions of uncertainty, complexity and change. Drawing on enactive cognitive science, the author presents a DE framework designed to augment traditional monitoring and evaluation activities. Discussing this framework in detail, the author also reports upon an extended case project investigating the sustainability of a market town in the UK. The framework aims to support the reader in capturing second-order learning and exploring opportunities for innovative responses to dynamic, uncertain and complex operational conditions. Recommendations are offered for future research, and how the framework might be incorporated into the design and funding of projects deployed to work with wicked problems.