Accession Number : AD0753009

Title :   Accuracy of the Mean Threshold and of the Variability in the Psychophysical Method of Constant Stimuli.

Descriptive Note : Phase rept.,

Corporate Author : NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA CREW SYSTEMS DEPT

Personal Author(s) : Herrick,Robert M.

Report Date : 19 OCT 1972

Pagination or Media Count : 39

Abstract : The methodology used to study the sensory capabilities of man in relation to display systems is psychophysics. One of the most common psychophysical methods in use is the Method of Constant Stimuli (MCS). Although the method has been in use for more than half a century, reliable estimates of the accuracy of the method are not available. To assess the accuracy of the MCS---specifically, the accuracy of the mean and standard deviation---simulations of MCS experiments were performed. In the simulations, the number of stimuli varied from 2 to 13, the number of judgments per stimulus varied from 10 to 320, the range of stimuli varied from a case where the probability (p) of a 'Yes' response for the extreme stimuli were p = .05 and p = .95 to a case where the extreme stimuli had associated p values of .40 and .60. Curves and equations derived from the simulation data give accurate estimates of the standard error of the mean threshold and of the 90% confidence limits of the standard deviation. (Author)

Descriptors :   (*PSYCHOPHYSICS, ACCURACY), (*DISPLAY SYSTEMS, PSYCHOPHYSICS), REACTION(PSYCHOLOGY), THRESHOLDS(PHYSIOLOGY), HUMAN FACTORS ENGINEERING

Subject Categories : Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE