The CoRE model was developed to account for the profound effects stimulus uncertainty can have on the discrimination of multitone patterns (an effect traditionally refered to as informational masking). The basic premise of the model is that listeners adopt an ideal decision strategy for the task but are incapable of ignoring much if any information in patterns that vary from trial to trial without constraint. In formal terms, listeners are assumed to integrate information over a rectangular time-frequency window with bandwidth and duration equal to or exceeding the bandwidth and duration of possible signals. Hence, if a given pattern is subject to a change in a parameter x of one or more tones, the listener's response is determined by the sum of x for all tones individually weighted by their amplitude-duration product: An internal noise factor is included to bound performance, but otherwise there are no additional assumptions. Average discriminability (d') for any ensemble of patterns is obtained from the expected value of the decision variable and its variance conditioned on whether or not there is a change in the pattern. This ultimately leads to the prediction that the magnitude of change required for a constant d' will be linearly related to the target component's relative entropy (CoRE) among patterns.
This precise relation of threshold to CoRE is demonstrated repeatedly in a review of past studies, and is shown to account for the effects of a variety of important variables and their interactions (Note: CoRE is the log of proportional variance). Such variables include the total duration of the pattern; number of tones in the pattern; number of tones subject to change; the relative level and duration of individual tones in the pattern; the relative variability and the physical dimension of the tones' parameters that are subject to change; the number and position of targets in the pattern; the psychophysical procedure used (method of adjustment versus same-different), the type of discrimination task (frequency versus intensity discrimination), and the manner of presentation of the tones (simultaneous or sequential).