Foster, D. H. and Bischof, W. F. (1997). Bootstrap Estimates of the Statistical Accuracy of Thresholds from Psychometric Functions. Spatial Vision, 11, 135-139.
Estimates of the accuracy of a threshold derived from a psychometric function are often based on asymptotic theory. When the number of trials is small, however, these estimates may prove untrustworthy. A computer program is described that uses the more robust bootstrap approach to obtaining estimates of the standard deviation and confidence limits of a threshold and of the slope and spread of the psychometric function, for any criterion level of performance.
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