The overall aim of WP5.1 is to synthesize and consolidate findings and methods gained in the UNCHAIN project, i.e. in the previous WPs. It brings together the insights gained in the case studies to develop a consolidated validation method (with a focus on impact chains (IC) and science-user interface) and identify opportunities for changes in adaptation decision making in Europe and beyond. Furthermore, it reflects on the process of stakeholder engagement and knowledge co-production to bridge the gap between climate science, policy and practice, and how related strategies could be improved. Specifically, this deliverable sets the basis for the validation and synthesis process to be carried out in WP5, with the aim to develop the following deliverables: D5.2 - Improved and adapted impact chain method (Guidebook and reflection on insights and lessons learnt) [as journal article and public report] D5.3. - Recommendations for improved adaptation decision making and policy [as policy brief] Therefore, this deliverable serves internal purposes to guide the validation process. It has been developed at an early-stage of WP5 to allow its uptake already during the case study research activities and its possible continuous update and evolvement during the remaining months of UNCHAIN.