Scenario reliability assessment to support decision makers in situations of severe uncertainty

Decision making under uncertainty is fraught with pitfalls for human thinking: biases prevail. The combination of a scenario-based approach with multi-criteria decision analysis assists in making value judgements, trade-offs and uncertainties explicit. Scenarios, which are constructed in a distributed manner involving multiple experts from different domains, assist in overcoming e.g. the prominence effect and confirmation bias. Furthermore, support is provided to handle the uncertainty associated with each scenario without imposing unjustified assumptions on each piece of information. We develop a relative reliability concept, which differs from standard probability assessments as it is sensitive to the context, such as the decision problem at hand, the decision makers' requirements and the available information. This approach maintains the flexibility of the distributed system by allowing the experts to adapt the information they provide and the likelihood assessments thereof to the situation. Our approach is illustrated by an emergency management example.