The Benefits of Covert Retrieval Practice on Short- and Long-Term L3 Vocabulary Retention

Background: The present study investigated the impact of retrieval practice on Japanese vocabulary acquisition by native Chinese speakers (English as the second language), employing a classic retrieval practice paradigm and examining both short-term and long-term effects. Methods: Fifty-eight Chinese participants without prior knowledge of Japanese learned 30 Japanese–Chinese word pairs through either repeated studying or retrieval practice. Participants subsequently provided metacognitive predictions before completing a 15-min delayed cued recall test, as well as 30-day and 50-day delayed old/new recognition memory tests. Results: Retrieval practice with feedback significantly enhanced vocabulary recall on the 15-min cued recall test and recognition on the 30-day and 50-day tests compared to repeated studying. Regarding metacognitive judgments, participants’ predicted performance significantly declined over longer retention intervals, but no significant differences were found between retrieval practice and repeated studying at any retention interval. Conclusions: The findings provide behavioral evidence for the advantage of retrieval practice in kana-based (phonographic) L3 vocabulary learning, extending the applicability of the desirable difficulties framework and the retrieval effort hypothesis to this context. The study also highlights the need to raise the awareness of retrieval practice among learners and educators. Future research should explore the generalizability of these findings to logographic (kanji) learning and to more ecologically valid educational settings.