Is Expanding Spacing More Effective than Equal Spacing for L2 Vocabulary Learning?

Abstract

　　It is widely known that spaced learning enhances long-term retention of learned items better than massed practice. Based on this finding, recent studies have examined which types of spaced learning, expanding or equal spacing are more effective, and found no significant difference between the two types of spaced learning. However, these studies asked participants to remember a relatively small number of target words. Therefore, both expanding and equal spacing groups in previous studies were able to master almost all the words during the learning sessions, and such a ceiling effect led to no significant difference. By increasing the number of target words to be learned, this study became original among the studies of spaced learning. Second-grade Japanese high school students learned 40 English and Japanese word pairs under either an expanding (Days 1, 3, 10, and 22) or equal spacing schedule (Days 1, 8, 15, and 22). Post-tests conducted on Day 29 and Day 57 revealed that the expanding group had a higher score than the equal spacing group. This indicates that an expanding spacing schedule is more effective than an equal spacing schedule when the number of words to be learned is large.