We examined how the format in which uncertainty information is presented affects two biases in humans' choice behavior. In a computer task, participants were given four common-ratio effect and four common-consequence effect problems in each of four different formats. In these problems, uncertainty information was described, as percentages (e.g., 80%) or as frequencies (e.g., 16/20), or was experienced, either serially (20 outcomes shown one at a time) or simultaneously (20 outcomes all shown at once). Presenting information as percentages attenuated the common-ratio effect and augmented the common-consequence effect, which suggests that these biases have different underlying mechanisms. Participants' percentage estimates of outcome likelihoods did not differ according to the format in which the information was presented; however, participants' nonverbal estimates of outcome likelihoods differed across formats. The results suggest that uncertainty information presented as percentages is processed differently than the same uncertainty information presented in other formats.
ASJC Scopus subject areas
- Psychology (all)