Frequency of occurrence as a psychophysical continuum: Weber's fraction, Ekman's fraction, range effects, and the phi-gamma hypothesis

Using the continuum of frequency of occurrence of words in English, it was found that: (1) errors in judgment are distributed lognormally rather than normally, and therefore the standard method of calculating Weber's fraction underestimates its definition, (2) Weber's fraction has an extremely large value of 3.3, (3)Ekman's fraction equals 1.81, not .03 as with sensory continua, and (4)the logarithm of the dynamic range times Stevens' law exponent equals 3.83, not 1.53 as with sensory continua. The last two results favor Teghtsoonian's underlying sensory scale interpretation over Poulton's range effects interpretation of the range-exponent relation. © 1976 Psychonomic Society, Inc.

Duke Scholars

Author David C. Rubin Psychology & Neuroscience