ABSTRACT
Comparisons against an Ideal are not comparisons of differences in magnitude but rather differences in similarity. C. H. Coombs proposed that the process of comparison might be of a different nature than that postulated by the Law of Comparative Judgment. Rather than comparing stimuli against each other, stimuli could be compared against an Ideal, a theoretical stimulus most favored of those qualitative stimuli. The nearer a stimulus was to the Ideal; the more likely it was to be preferred over an alternative stimulus more distant from the ideal. Nearly 30 years later, Gustav Fechner, former professor of physics at Leipzig University, created the first theory of mental comparison in order to measure the 'imperfections of our senses'. Fechner assumed that the nervous system introduced imperfections in the measure of physical stimuli due to intrusions of the type of measurement error described by Karl Gauss. A fixed stimulus generated a variable internal intensity due to the influence of Gaussian error.
