Average Exponent from Magnitude Production

When magnitude production is used to obtain a psychophysical power function for a group of Ss, the group exponent is shown to be the harmonic mean of individual-S exponents under the conditions usually employed in empirical research. The conditions are (a) the same numbers are presented to each S, (b) responses to each number are pooled over Ss by taking geometric means, and (c) the function is fit by the method of least squares in which regression is of the logarithm of Ss' responses upon the logarithm of numbers presented by E.