TY - JOUR
T1 - Fifty-fifty=50%?
AU - Fischhoff, B.
AU - Bruine de Bruin, W.J.A.
PY - 1999
Y1 - 1999
N2 - Several recent surveys have asked respondents to estimate the probabilities of relatively unlikely events, such as dying from breast cancer and smoking. Examination of their response distributions reveals a seemingly inappropriate ‘blip’ at 50. The two studies reported here indicate that it reflects a response artifact associated with open-ended probability scales. The blip vanishes when a response scale with explicit response options is offered. Apparently, the open-ended format leads some people to use the 50% option as ‘fifty–fifty’, an expression of having no idea as to the answer. As a result, the accuracy of people's reported beliefs depends on the response scale used, as well as on how it evokes and channels such feelings of epistemic uncertainty.
AB - Several recent surveys have asked respondents to estimate the probabilities of relatively unlikely events, such as dying from breast cancer and smoking. Examination of their response distributions reveals a seemingly inappropriate ‘blip’ at 50. The two studies reported here indicate that it reflects a response artifact associated with open-ended probability scales. The blip vanishes when a response scale with explicit response options is offered. Apparently, the open-ended format leads some people to use the 50% option as ‘fifty–fifty’, an expression of having no idea as to the answer. As a result, the accuracy of people's reported beliefs depends on the response scale used, as well as on how it evokes and channels such feelings of epistemic uncertainty.
U2 - 10.1002/(SICI)1099-0771(199906)12:2<149::AID-BDM314>3.0.CO;2-J
DO - 10.1002/(SICI)1099-0771(199906)12:2<149::AID-BDM314>3.0.CO;2-J
M3 - Article
SN - 0894-3257
VL - 12
SP - 149
EP - 163
JO - Journal of Behavioral Decision Making
JF - Journal of Behavioral Decision Making
ER -