We wish to thank everyone that joined the Impact Evaluation Working Group (IEWG)’s events at ECCB 2026 in Leiden! To recap what we did together:

Symposium: Evidence and Attribution in the Age of Novel Data, Methods, and Technologies (July 7th)
We hosted a symposium that brought together 5 great speakers that showcased how new data, methods, and technology are reshaping conservation impact evaluation. The session opened with big-picture framing around AI and automation for evidence-based conservation at scale (Tanya O’Garra), then moved through applied case studies, from using Earth observation advances to assess protected area effectiveness (Saija Papunen), evaluating conservation spending via local ballot measures (Joséphine Gantois), and detecting national-level policy signals in deforestation trajectories (Jakob Poffley). It closes with a talk on the state of reproducibility in conservation science impact evaluations (Alex Caruana), tying the session back to its broader themes of attribution, counterfactual thinking and transparency. It was great to see a full lecture theatre of conservationists interested in impact evaluation present.

Social Event at Bierlokaal De Veste (July 7th)
Later that evening around 20 of us gathered together in central Leiden for food, drinks, and lively conversation to follow-up our symposium. We want to thank everyone who joined our events for making this experience great, and we hope to see you at future conferences!