Testing the Effects of Thematic Uncertainty on Spatial Decision-making

The output of any Geographic Information System (GIS) is a representation of the real world and, as such, it will always contain some level of uncertainty. There is now a growing recognition that this uncertainty should be communicated to information consumers if they are to be fully informed regarding the decisions being made on the basis of the underlying data. Research to date has tended to focus on the issues of how uncertainty information can be modeled and visualized, with less consideration being given to the subject of how users might apply such information. Studies in the psychological literature clearly indicate decision-making biases when information is ambiguous, with most people displaying ambiguity aversion. Therefore, the research question we seek to answer in this paper is “Do people exhibit a similar bias towards uncertain spatial information?” This paper examines the effects of introducing thematic uncertainty to spatial information in the context of a decision task. The results indicate that many people, including those who consider themselves to be experienced in working with spatial information, do not have an intuitive understanding of how to handle uncertainty in decision-making. Furthermore, our findings reveal that the inclusion of uncertainty information in a GIS output can lead to irrational decisions being made—instead of promoting robust, more fully informed decision-making as intended.