A random walk model of digit comparison (Q1117869)

To choose the greater of two digits, information in memory about the digit values must be compared. Like comparisons of values on perceptual dimensions, the response time and the probability of error for digit comparisons increase as the difference in the digit values decreases. A random walk model of the comparison process explains these distance effects. Six subjects participated in three experiments to test the model. The model accounted for general features of the relationship between speed, accuracy, and the digit values, as well as the effects of response time deadlines. Modifications to the model are considered to account for the observed dependence of response biases on stimulus values.