1. A data-processing system comprising: one or more processors; one or more computer-readable media; and a routine stored in the computer-readable media that when executed on the one or more processors, receives a set of feedback statistics, each feedback statistic represents a level of user satisfaction with a belief; calculates weighted statistics of the feedback statistics; calculates an entropy of the weighted statistics based on frequencies of occurrence of the weighted statistics; calculates a confidence value for the belief based on the entropy of the weighted statistics associated with the belief; calculates a rank value for the belief based on the confidence value and an average of the weighted statistics; and stores the rank value in the one or more computer-readable media.