Temporal aspects of digit and letter inequality judgments

The time needed for adults to indicate which of. two digits is larger, which of two digits is smaller, and which of two letters appears later in the alphabet was studied in three experiments. Latencies in both digit tasks were primarily a linear increasing function of the minimum digit of each pair, with responses for indicating the larger digit approximately 40 msec, faster than those for indicating the smaller digit. Latencies for the letter task were approximately 200-300 msec, longer than the reaction times for digits. Furthermore, the pattern of latencies for individual letter pairs was substantially different from the patterns for corresponding digit pairs, suggesting underlying process differences for the two types of material. Moyer and Landauer (1967) investigated the time required to judge which of two simultaneously presented digits is larger and found latencies to be a monotonically decreasing function of the absolute numeri-cal difference (Split) between the digits. Fairbank (1969) replicated this finding and, furthermore, found similar results when either months of the year or letters of the alphabet were substituted for digits. In addition, Fairbank showed that when 5s are required to select the smaller of two simultaneously presented digits, more tim