Expert Judgement for Geological Hazards in New Zealand

Expert judgement is important for the short- and long-term assessments of natural hazards in New Zealand, contributing to their risk analyses and informing decision-making. The problems are complex and usually require input from experts from different sub-disciplines. Expert judgement, like all human cognitive processes, is prone to biases. Therefore, we aim to use methods that are robust, transparent, reproducible and help reduce biases. The Classical Model treats expert opinion as scientific data and its performance-based weighting of experts allows us to measure the uncertainty of a quantifiable problem. We have developed a protocol for risk assessment, including structured expert judgement, which is centred around workshop-style interactions between experts to share knowledge. The protocol borrows heavily from the framework for the risk management process of the International Organization for Standardization. We outline seven recent applications of structured judgement, mostly in seismology and volcanology. Most of them use the Classical Model to aggregate the expert judgement. We discuss challenges and insights, concluding that developing an optimal protocol for expert judgement is a continuing journey.