Predicting proficiency

We investigated which objective language proficiency tests best predict the language dominance, balance, English and Spanish proficiency scores relative to Oral Proficiency Interview (OPI) scores (averaged across 5–6 raters). Eighty Spanish–English bilinguals completed OPIs, picture naming, semantic and letter fluency, lexical decision tests and a language history questionnaire. Except for letter fluency, objective measures explained more variance than self-report variables, which seldom and negligibly improved proficiency prediction beyond objective measures in forward regression models. Picture naming (the Multilingual Naming Test (MINT) Sprint 2.0) was the strongest predictor for most purposes. Lexical decision and category fluency were next best predictors, but the latter was time-consuming to score, while the former was easiest to administer (and does not require bilingual examiners). Surprisingly, self-rated proficiency better predicted the OPI scores when averaged across modalities (i.e., including reading/writing instead of just spoken proficiency), and lexical-decision (a written test) was as powerful as picture naming for predicting spoken Spanish (but not language dominance).