Symmetry in Decision Evaluation

Several models for handling vague and imprecise information in decision situations have been suggested. In those contexts, various interval methods have prevailed, i.e. methods based on interval estimates of probabilities and, in some cases, interval utility estimates. Even if these approaches in general are well founded, little has been done for demon-strating whether the approaches are comprehensi-ble for a decision maker. In particular, it is far from always clear what is actually expressed by a set of intervals where linear dependencies do occur. Furthermore, it is difficult to find rea-sonable decision rules that select an alternative out of a set of alternatives and correspond to the intuition of a decision maker. In this article, we investigate some problems that are inherent in interval approaches and suggest how the choice of particular evaluation rules might compensate for this.