Graphical Communication of Uncertain Quantities to Nontechnical People

Nine pictorial displays for communicating quantitative information about the value of an uncertain quantity, x , were evaluated for their ability to communicate x̄ , p ( x > a ) and p ( b > x > a ) to well‐educated semi‐and nontechnical subjects. Different displays performed best in different applications. Cumulative distribution functions alone can severely mislead some subjects in estimating the mean. A “rusty” knowledge of statistics did not improve performance, and even people with a good basic knowledge of statistics did not perform as well as one would like. Until further experiments are performed, the authors recommend the use of a cumulative distribution function plotted directly above a probability density function with the same horizontal scale, and with the location of the mean clearly marked on both curves.