ABSTRACT
A continuing problem in modern psychophysics is the variations in psychophysical scales that occur across different judgmental tasks and/or different subjects. That is, when the same subjects participate in different judgmental tasks, the form of the resulting scale may change. For example, scales based on subjective ratios (e.g., magnitude scales) do not agree with those based on subjective differences (e.g., category scales). Moreover, the form of a psychophysical scale may also change considerably across different subjects who participate in the same judgmental tasks. For example, the exponents of power functions relating magnitude scales of loudness for individual subjects to physical stimulus values may change from .05 to .35 (McGill, 1960).
