In any language, it’s rare to speak in a conversation without listening to the other person, or to write a passage of text without reading it. While many standardised English language tests break down questions into reading, writing, listening and speaking, the Duolingo English Test (DET) is structured so that test takers can show how they use these skills in combination.
The DET consists of a computer-adaptive portion and an extended-response portion: the former is a series of questions that become more or less difficult based on the test taker’s performance; the latter comprises open-ended written, audio, and visual prompts. For example, certain questions require test takers to describe an image in a written or spoken paragraph.
“The adaptive items all have an objectively correct answer, so we’re able to score these in real time and administer the test adaptively,” explains Ramsey Cardwell, DET assessment scientist at Duolingo.
Results from the open-ended questions – which are more difficult to assess due to a number of factors, including grammar, frequency of words, speed and the variability of vocabulary – are combined with the adaptive scores to offer a full picture of language proficiency to university admissions teams.
An adaptive test means users don’t spend time on questions that are far above or below their proficiency level. Traditional fixed-form tests, by comparison, must contain questions to evaluate all proficiency levels, meaning they take longer to complete. With the DET, fewer items are needed to accurately assess the student’s proficiency, so the test can be done in just an hour.
The adaptive feature of the test is made possible by a machine learning model known as GPT-3, which can generate large numbers of test items that are reviewed for appropriateness. This “human-in-the-loop” approach enables test questions to be developed efficiently and affordably, supporting the security and accessibility of the test, Cardwell says. Users experience a variety of question types, the combination of which adds up to a “naturalistic view of someone’s proficiency”.
An adaptive question might ask students to select the best option for a missing word in a passage, or listen to a spoken sentence and write what they hear. Other questions might ask them to click and drag text to highlight the answer to a question, or to select the idea that is expressed in the passage.
One recurrent question asks test takers whether words are real or fake. “This type of item taps into the psycholinguistic sphere, your intuition or instinct for language,” Cardwell explains. “If someone has seen or used the word many times before, they will have a familiarity with it.”
The best way to prepare for the DET is to immerse oneself in the language. Students can take a practice test on the DET website, and there are tips on how to navigate different types of questions. Readiness materials are freely available and are not designed to help students “game” the test.
“Our materials explain the types of items, so you’re not tripped up,” Cardwell says. “We also emphasise that listening and speaking English is the key to improvement.”
Find out more about the Duolingo English Test.
It’s rare for a high-stakes language test to cover a range of proficiency levels in just one hour. We look at how the adaptive structure of the Duolingo English Test provides a granular view of ability while being accessible to students