Fig. 6.

Iterative bootstrap and observed information variance estimate error on μ̂_i and σ̂_i (the estimates for the i^th data set) for a 3-down/1-up staircase 0.5 and 1for n = 50 trials (panels a–d) and n = 200 trials (panels e–h). Panels a, c, e and g) show the histograms for the error on the variance estimates of μ̂_i and σ̂_i using the iterative bootstrap technique. Panels b, d, f and h) show the histograms for the error on the variance estimates of μ̂_i and σ̂_i using the observed information technique. The solid black line shows 0% error, the solid gray line is the mean error, and the dashed gray lines indicate one standard deviation either side of the mean error