Resistance of the Spacing Effect to Variations in Encoding

Abstract

Orienting tasks were employed in two experiments to examine the encoding variability explanation of the spacing effect. Subjects were presented word lists that included items that were repeated with either no items or five items intervening between presentations. In addition, the orienting task required was the same or different on the two presentations. According to the encoding-variability hypothesis, the orienting tasks should tend to override the usual effect of spacing of repetitions by encouraging or discouraging variable encoding. However, free recall of the lists revealed significantly better performance with spaced repetitions, independent of the orienting tasks, thus disconfirming the hypothesis.