Testing the scenario hypothesis: The effect of alternative characterizations of uncertainty on decision structuring

Min Gong, David Krantz

There is much current interest in decision support approaches to help improve groups’ and individuals’ ability to make difficult decisions, such as those planners must make when considering uncertain, long-term environmental changes. Decision research and decision support generally focus on how people do and should choose among a fixed set of options.  However, for many decisions facing policy makers, designing an option that reduces difficult tradeoffs (part of structuring a decision) is at least as important as choosing among existing options. An additional complication arises in the presence of deep uncertainty where decision makers may be unsure about the structure of the situation making it difficult for them to understand or agree on the potential consequences of alternative options, and thus to effectively design new ones. Based on such observations from the literature, and our own extensive experience using decision support tools to help policy makers make decisions, we hypothesize that decision support processes that employ scenarios to characterize deep uncertainty will help contentious groups make more effective decisions than decision support processes that characterize uncertainty using a single set of best-estimate probability distributions.

Broader Impacts

• The results of these experiments will shed light onto the social and psychological processes involved in complex, deeply-uncertain policy decisions, inform improvements in decision support methodologies, and contribute to ongoing policy discussions regarding the most effective means of conveying deeply uncertain information.