Improving second language vocabulary learning and retention by leveraging memory enhancement techniques: A multidomain pedagogical approach

We investigated whether learning and retaining vocabulary in a second language (L2) can be improved by leveraging a combination of memory enhancement techniques. Specifically, we tested whether combining retrieval practice, spacing, and related manipulations in a 'multidomain' pedagogical approach enhances vocabulary acquisition as compared to a typical learning approach. In a classroom-laboratory design, 48 Turkish university students studying L2 English were trained on 64 English words over 17 days. They were assigned to either a 'typical' study regimen of (re)studying the words on the first day (initial study) and last day (cramming) of training, or an 'optimized' regimen of retrieval practice (retrieving the words), moreover with feedback, spaced throughout the period, moreover with expanding gaps. The target words were tested before training (pre-test) and one and 11 days afterwards (post-tests). Mixed-effects modeling revealed a training-group by test-session interaction, due to greater improvements from optimized training (a striking 18 percentage-point accuracy increase from pre-test to both post-tests) than typical training (an 8 percentage-point increase). Further analyses showed that the optimized training advantages were mainly driven by high (rather than low) frequency words. Overall, the results suggest that a multidomain approach of combining different memory enhancement techniques can lead to substantial gains in both the learning and retention of L2 words, as compared to a typical study pattern. The findings have implications for L2 learning and pedagogy.