List differentiation and the point of interpolation in free-recall learning

Abstract

In two experiments Ss learned two lists of unrelated items by free-recall learning. For list differentiation (LD), both lists were presented in a mixed order and S identified the list membership of each item. In Experiment I the interval between List-1 learning and the LD test was 48 hr.; List 2 was learned either 0, 24, or 48 hr. after List 1. The third condition showed superior LD to the other two, which did not differ. In Experiment 2, LD followed List 2 immediately, and List 2 was learned either 0 or 48 hr. after List 1. With 4 or 6 trials of List-2 learning the 48 hr. condition showed superior LD, the 0 condition with 2 trials. It was concluded that point of interpolated learning affects the difference in relative strength between competing lists, on which LD largely depends.