Decision-making under interval uncertainty revisited

Purpose - In many real-life situations, we do not know the exact values of the expected gain corresponding to different possible actions, we only have lower and upper bounds on these gains - i.e., in effect, intervals of possible gain values. The purpose of this study is to describe all possible ways to make decisions under such interval uncertainty. Design/methodology/approach - The authors used both natural invariance and additivity requirements. Findings - The authors demonstrated that natural requirements - invariance or additivity - led to a twoparametric family of possible decision-making strategies. Originality/value - This is a first description of all reasonable strategies for decision-making under interval uncertainty - strategies that satisfy natural requirements of invariance or additivity.