The comparison of a series of proportions: the problem and a new solution.

Effects of Anxiety and Morphine on Discrimination of Intensities of Painful Stimuli

“…For purposes of graphic presentation, the mean percentage of "stronger" judgments of each scale step was plotted against the mean power delivered and 5Although the Spearman Summation Method does not weight errors, it does afford a rather accurate means of converting "stronger" judgments into power when the scale steps are not entirely equivalent. When scale steps are equal the method advocated by Davis (13) would seem more appropriate.…”

Chapter VI: Computational Technics

“…Davis (29) indicated that traditional methods of calculating psychophysical parameters from percentage data left much to be desired since their sampling errors were not known. He suggested that if the regression of transformed proportions on the stimulus scale were calculated, the appropriate standard error would be the standard error of estimate.…”