Duolingo: The Duolingo English Test is the first major standardized language proficiency exam where AI handles every stage of the process — writing the test questions, calibrating their difficulty, choosing which questions each test-taker sees, grading answers, and producing final scores. The test costs $65, takes about an hour, and is accepted by more than 5,000 universities worldwide. | AI Trace
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The Duolingo English Test is the first major standardized language proficiency exam where AI handles every stage of the process — writing the test questions, calibrating their difficulty, choosing which questions each test-taker sees, grading answers, and producing final scores. The test costs $65, takes about an hour, and is accepted by more than 5,000 universities worldwide.
Details
Described in a peer-reviewed 2020 paper published in MIT Press's Transactions of the Association for Computational Linguistics, the Duolingo English Test uses machine learning and natural language processing (NLP) models to automatically generate thousands of test items and align them to CEFR proficiency levels. A computer-adaptive testing approach means each test-taker sees a customized set of questions selected in real time based on their performance, so no two tests are identical. Scores on the 10–160 scale correlate with TOEFL and IELTS at .73 — comparable to the correlation those two tests have with each other. A test-taker would encounter a repeated item only after approximately 1,000 sessions, demonstrating the system's breadth.
