R. R. Yager [Int. J. Gen. Syst. 8, 139-146 (1982; Zbl 0487.90007)] presents a model based on fuzzy mathematics of the confidence people have in their own decisions. Previous empirical studies indicate that differences exist between self-reported measures of post-decision confidence and Yager’s predicted measures of decision tranquility. The purpose of this article is to demonstrate that some
... [Show full abstract] systematic differences are a result of attractors, round numbers which appear reasonable at or near special cases even though they depart from a broader pattern. The results indicate that the strength of the attractors varies as a function of the decision structure. Subjects reported their confidence in a choice based on alternatives using random sets, a special case of fuzzy sets. Subjects’ self-reported measures of decision confidence were analyzed, and the frequencies of responses were compared by decision type. Three decision structures which appear to increase attractor strength were identified. Univariate t-tests of the differences of mean response frequencies between decision structure types were significant at the .05 level. These results raise some potentially fruitful research issues with respect to Kahneman’s prospect theory, Smet’s work on plausibility, belief and pignistic probabilities and Yager’s concept of immediate probability.