Studies in subjective probability IV: probabilities, confidence, and luck

Probably because of formal advantages, probabilities are often regarded as more basic than other dimensions of attitudes towards uncertain events (beliefs, confidences, doubts, statements of hope and fear, good and bad luck etc.). In a series of experiments, some of these concepts were empirically compared by asking students to give their views on a variety of uncertain events, ranging from future examinations to lotteries. Confidence turned out to be closely related to perceived chance, but very imperfectly to the subjective probability of the event in question, except when all outcomes are judged equally due to chance. Judgments of good and bad luck were still more independent of the probabilities involved, even in a chance situation, It is concluded that subjective probability plays a secondary role in assessments of confidence as well as of luck, and is poorly suited as a common measure of the varieties of subjective uncertainty. A final experiment suggests the subjective and statistical conceptions of uncertainty to have partially opposing connotations. "An uncertain future" seems to be subjectively interpreted as an open future, restricted possibilities of prediction.