OCHA's annual World Humanitarian Data and Trends highlights major trends in the nature of humanitarian crises, their causes and drivers, and participation in crisis prevention, response and recovery. Beyond providing statistics, the trend analysis shows how the humanitarian landscape is evolving and how the humanitarian system can be more effective in a rapidly changing world. Data used in the report comes from a variety of sources: collaborative partners - such as the Qatar Computing Research Institute, IDMC and Development Initiatives - as well as from organizations and publications with subject-matter expertise: The World Bank, UNHCR, Heidelberg Institute and UNDP among others. Highlights for 2015 include case studies on long-term trend analysis of the humanitarian context in terms of conflicts and natural disasters, the humanitarian footprint in the Middle East, coordination of online volunteers during the Ebola response and the anatomy of cycles of displacement. The report aims to provide a "one-stop" shop for policy makers, researchers and humanitarian practitioners to have an evidence-base and advocacy tools for humanitarian assistance. Overall, this report is one part of OCHA's efforts to improve data and analysis on humanitarian situations worldwide.