Long · Behavioral sciences (Basel, Switzerland) 2026 · randomized controlled laboratory experiment · n=58

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

Level 2 - randomized trial

Individual randomized experimental trial

PubMed 42510245 · doi:10.3390/bs16071124 · record verified 2026-08-26

What was done

Fifty-eight native Chinese speakers with L2 English and no prior Japanese knowledge learned 30 Japanese-Chinese word pairs through either repeated studying or retrieval practice with feedback. Participants made metacognitive predictions before taking a 15-minute delayed cued recall test, as well as 30-day and 50-day delayed old/new recognition memory tests.

What was found

The abstract reports no exact numerical values, percentages, or effect sizes. Retrieval practice significantly enhanced vocabulary recall on the 15-minute cued recall test and recognition on the 30-day and 50-day tests compared to repeated studying. Metacognitive predictions declined across longer retention intervals, but participants showed no significant difference in predicted performance between the two study conditions at any retention interval.

Why it matters

The study shows that the testing effect extends to phonographic third-language vocabulary retention up to 50 days, while demonstrating that learners fail to metacognitively recognize the superior efficacy of retrieval practice over repeated study.

Limits

The sample is small (n = 58) and limited to Chinese native speakers learning kana-based Japanese words in a laboratory paradigm rather than an applied classroom setting. Long-term retention was assessed via recognition rather than productive recall, logographic (kanji) learning was not evaluated, and no numerical test statistics or effect sizes were reported in the abstract.