The effects of tests on learning and forgetting

In three experiments, we investigated whether memory tests enhance learning and reduce forgetting more than additional study opportunities do. Subjects learned obscure facts (Experiments 1 and 2) or Swahili-English word pairs (Experiment 3) by either completing a test with feedback (test/study) or receiving an additional study opportunity (study). Recall was tested after 5 min or 1, 2, 7, 14, or 42 days. We explored forgetting by means of an ANOVA and also by fitting a power function to the data. In all three experiments, testing enhanced overall recall more than restudying did. According to the power function, in two out of three experiments, testing also reduced forgetting more than restudying did, although this was not always the case according to the ANOVA. We discuss the implications of these results both for approaches to measuring forgetting and for the use of tests in promoting long-term retention. The stimuli used in these experiments may be found at www.psychonomic.org/archive.