Published online by Cambridge University Press: 01 January 2025
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.
This paper was supported in part by grant no. APA-151 from the National Research Council of Canada. The author wishes to thank William W. Rozeboom for his helpful comments on this paper.