TY - JOUR AU - Grossman, E. R. F.W. AB - QUARTERLY JQURNAL OF EXPERIMENTAL PSYCHOLOGY BY E. R. F. W. CROSSMAN From the Psychological Laboratory, Cambridge” The need for a quantitative measure of “Discriminability” is pointed out. A formula is required which will enable one, knowing the physical measurements of a set of sensory signals, to predict the time taken by a human observer to recognize any one. Existing formulse relate to the two-choice threshold task and to very “easy” multi-choice ones. A more general treatment is attempted in order to cover the region between these two special cases. For the limited case of two-choice one-dimensional signals, three functions fulfilling the requirements have been derived from theoretical considerations and tested against observed times for visual and proprioceptive sorting tasks of various levels of “difficiilty.” The function : K where xl, xz = physical sizes of signals, I, 2 c (I, 2) = K = an arbitrary constant 1 log. XI -=I was chosen as fitting the data most adequately, and has been named the Confusion- function. A method of extending its use to multi-choice and multi-dimensional signa-sets is outlined and experimental results concerning the former are presented. The relation between this function and the 1Veber-Fechner law is discussed ; TI - The Measurement of Discriminability JF - Quarterly Journal of Experimental Psychology DO - 10.1080/17470215508416692 DA - 1955-12-01 UR - https://www.deepdyve.com/lp/sage/the-measurement-of-discriminability-AicO9iVEWT SP - 176 EP - 195 VL - 7 IS - 4 DP - DeepDyve ER -