When additional multiple-choice lures aid versus hinder later memory

Three experiments were conducted to investigate whether increasing the number of lures on a multiple-choice test helps, hinders or has no effect on later memory. All three patterns have been reported in the literature. In Experiment 1, the stimuli were unrelated word lists, and increasing the number of lures on an initial multiple-choice test led to better performance on later free recall and cued recall tasks. In contrast, in Experiments 2 and 3, stimuli were facts from prose materials, and increasing the number of multiple-choice lures led to robust costs in cued recall and smaller costs in free recall. The results indicate that performance on the initial multiple-choice test is a critical factor. When initial multiple-choice performance was near ceiling, testing with additional lures led to superior performance on subsequent tests. However, at lower levels of multiple-choice performance, testing with additional lures produced costs on later test.