Four groups of 40 Ss were given transfer tests following 2.4, 6, or 8 14-trial blocks of paired-associate training with unequal stimulus frequencies and then retested after a further training period in which the same compound stimuli were presented at equal frequencies. The novelty effect, in which Ss respond to new combinations of training components by giving the response associated with the least frequent component, was obtained in every transfer test. It was concluded that the novelty effect is a mode of responding that is produced by differential frequencies during early learning and which, once adopted, is retained by Ss regardless of whether the frequency differential is maintained.