抄録
The present study aims to compare the effects of expanding and equally-spaced retrieval practice on long-term L2 vocabulary retention. Since the discovery of Ebbinghaus’ forgetting curve, expanding retrieval practice has been considered more effective than equally-spaced retrieval practice. Learners have been encouraged to review target items immediately after the first learning session, and then extend intervals between study sessions gradually, rather than have the same interval period between each session. The present study challenges this assumption. Participants in Group A (n = 34) learned 20 target words under the expanding condition (Day 1, 1, 8 and 22), while those in Group B (n = 19) learned the same 20 target words under the equally-spaced condition (Day 1, 8, 15 and 22). Twenty-one days after the learning session (Day 43), both groups took a delayed post-test, where they were asked to recall Japanese meanings for the English target words. This study revealed that the expanding group showed significantly better results than the equally-spaced group just after the first review session. However, there was no significant difference in long-term retention between the two forms of spaced learning, as long as both groups were given the chance to have four learning sessions.
