Spacing judgments as an index of study-phase retrieval.

It is hypothesized that the ability of subjects to judge how far apart two presentations of a word were in a list reflects study-phase retrieval of the trace of the first presentation of the word by its second presentation. Ex-periment 1 supported this hypothesis by demonstrating that the accuracy of spacing judgments for associatively related pairs of words, like that for repeated words, was high compared to that for unrelated words. Experi-ment 2 used spacing judgments to measure retrieval upon repetition of a homograph. In three conditions, context words accompanying a homograph on its two presentations were either the same, biased the same meaning, or biased different meanings. In all three conditions, later spacing judg-ments were more accurate than in an unrelated-word control. Accuracy did not depend on whether the two context words biased the same meaning or different meanings of the homograph. If a subject studies a word list in which some of the words occur twice, and later