What can errors tell us about differences between monolingual and bilingual vocabulary learning?

Error patterns in vocabulary learning data were used as a window into the mechanisms that underlie vocabulary learning performance in bilinguals vs. monolinguals. English-Spanish bilinguals (n = 18) and English-speaking monolinguals (n = 18) were taught novel vocabulary items in association with English translations. At testing, participants produced English translations for the newly-learned words. Findings revealed broad learning advantages in the bilingual data. Moreover, bilinguals made proportionately more deep (within-category) semantic errors than monolinguals when tested immediately after learning. We interpret these data to suggest that bilingual learners may encode the information associated with the novel words to a deeper semantic level than monolinguals.