 There are more complicated choice rules that depend on a richer representation of uncertainty involving a notion of confidence. For instance, Klibanoff et al. (2005) propose a rule whereby choices are made between otherwise incomparable options on the basis of confidence-weighted expected utility. It presupposes that weights can be assigned to the various expected utilities associated with an act, reflecting the agent’s confidence in the corresponding probability and utility pairs. There are alternative rules that appeal to confidence even in the absence of precise cardinal weights. Gärdenfors and Sahlin (1982), for instance, suggest simply excluding from consideration any probability (and utility) functions that fall below a confidence threshold, and then applying the Maxmin-EU rule based on the remainder. Hill’s (2013) choice theory is somewhat similar, although confidence thresholds for probability and utility pairs are allowed to vary depending on the choice problem (and the term “confidence” is itself used differently). There are further proposals whereby acts are compared in terms of how much uncertainty they can tolerate (which again depends on levels of confidence) and yet still be a satisfactory option (see, e.g., Ben-Haim 2001). These rules are compelling, but they do raise a host of difficult questions regarding how to interpret and measure the extra subjective attitudes that play a role, like “amount of confidence in a belief/desire” and “satisfactory level of desirability”.