Developmental Evaluation is an analytical approach that uses information collection, sense-making and evidence-based decision support to facilitate adaptive management of complex social programs and interventions. It is needed because development challenges are often "wicked problems" that are complex with unclear boundaries and unpredictable dynamics. Developmental Evaluation uses tools like Most Significant Change narratives, dashboards, and sentinel indicators to help platforms and partners continuously learn and adapt their approaches over time in response to changes in these complex systems. Good practices for Developmental Evaluation emphasize using multiple methods at different scales, facilitating intentional learning discussions, balancing rigor with useful information, and fostering partnerships focused on joint learning rather than transactional relationships.