Comparison of Distortion of Probability information in Decision under Risk and an equivalent Visual Task

摘要

Decision makers typically overweight small probabilities and underweight large. However, there are recent reports that, when probability is presented in relative frequency form, this typical pattern reverses. We tested this hypothesis, comparing decision making in two decision tasks, in which probability was either stated numerically or conveyed through a visual representation. In the visual task, participants chose between firing a ‘stochastic bullet’ at a large target for a small reward or at a small target for a large reward. Participants’ knowledge of probability in the visual task was the results of extensive practice firing bullets at targets. In the classical numerical task, they chose between pairs of lotteries with probabilities and rewards matched to those in the visual task. We found that participants had significantly different probability weight functions in the two tasks but the pattern for the visual task was the typical, not the reversed, pattern.