Fig. 7.

Parameter distributions show parameter estimates for 10,000 simulated experiments with 20 and 100 trials. The columns from left to right represent the fitted psychometric width parameter ($\widehat{\sigma }$), the fitted confidence scaling factor ($\widehat{k}$), and the fitted psychometric function bias ($\widehat{\mu }$) as shown on the x-axis at bottom. A and D: fitted parameters of conventional binary forced-choice parameter estimates. B and E: fitted parameters estimates determined via our CSD model fit for a well-calibrated subject (k = 1). C and F: fitted parameters estimates determined via our CSD model fit for an underconfident subject (k = 2). The solid black line shows the actual parameter value (i.e., μ = 0.5 or σ = 1), the solid gray line shows the mean of fitted parameters, and the dashed gray lines indicate SD on each side of the mean.