Physicochemical characteristics and supraliminal odor intensity: Reply to Mitchell

The rate of growth (exponent) of the psychophysical function for odor intensity depends upon the physicochemical properties of odorous substances. Although no single property is able to predict rate of growth, a model developed by Dravnieks and Laffort that combines three basic properties has been quite successful. The results of intra-O comparisons of the relative exponents for various odorants have withstood the test of replication, i.e., variation among Os has usually not been a serious problem. In the future, comparisons of the exponents obtained from one laboratory to another would be aided considerably by inclusion of a standard odorant in all scaling studies.