Judgment of short time intervals while performing mathematical tasks

Ornstein (1969) suggested that the apparent duration of a time interval depended upon the memory storage size. This experiment tests this theory by studying duration estimates made while performing different types of information processing. Twenty Ss, introductory psychology students, served in each of the 30 conditions of the experiment. The six time intervals estimated by the method of reproduction were of lengths of 10, 12, 14, 16, 18, and 20 sec, and the five intervening tasks were doing nothing, reading numbers, adding, multiplying, and adding and multiplying in a random order. The results show that fewer items were output in the three arithmetic conditions, as compared with the reading condition, and also show that the duration estimates were shorter for these three conditions. Estimates of duration are related to amount of output, and also appear to be related to the type of processing done to produce this output.