Abstract: In order to compare the merits of SDT and classical psychophysical methods twoexperiments on weight discrimination were carried out on subjects of different ages,sexes and occupations. Both SDT and the method of constant stimuli were used. Ithas been shown that when the subject's response bias is not influenced by the changeof experimental conditions, the measurement of sensitivity by the method of constantstimuli is just as efficient as that by SDT. But when some non-sensory factors havean effect on the subject's response bias, the measurement of sensitivity by SDT is morereliable. The authors hold that although SDT has been considered a powerful tool tomeasure sensitivity, the clasaical psychophysical methods are still useful under certainappropriate conditions. They are indispensable methods in sensitivity studies, and can-not be replaced by SDT.

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