For decades, traditional test centers have been seen as the gold standard for high-stakes exams. Rows of desks, a watchful proctor, and a strict set of rules have long been considered enough to ensure test security.
But in reality, test centers aren’t nearly as secure as they seem.
In-person testing environments present plenty of opportunities for cheating—from discreetly hidden notes to subtle hand signals or even high-tech devices that slip past distracted proctors. And that’s not to mention the potential for people to bribe invigilators, or pay someone to use a fake ID and sit the exam for you.
That’s why from the very beginning, we designed the Duolingo English Test (DET) with security in mind. By leveraging AI, automation, and multi-camera monitoring, the DET eliminates the blind spots and vulnerabilities that test centers struggle to control.
The problem with test centers: easy-to-miss cheating tactics
Test centers may have proctors, but in-person human supervision has natural limitations. A single proctor is often responsible for monitoring dozens of test takers at once, meaning it’s easy to miss subtle—or even blatant!—forms of cheating.
Some of the most common ways people try to cheat in test centers include:
- Using a fake ID to impersonate another test taker
- Hiding notes or cheat sheets under their sleeves, desks, or clothing
- Receiving hand signals or whispered answers from a nearby test taker
- Using concealed technology, such as smartwatches, invisible earpieces, or camera-equipped glasses
- Memorizing or leaking test content to share with future test takers
Even if a proctor notices something suspicious, they may not always be able to act immediately. But sometimes, test takers don’t even need to cheat on their own—proctors or test center employees themselves may be involved. Corrupt test center staff have been caught providing answers, allowing test takers to switch places, or even modifying results after the test—all in exchange for money. In high-profile cases, entire networks of fraudulent test centers have been exposed, operating for years before being shut down.
With these vulnerabilities, test-center-based exams aren’t as secure as many assume. That’s why at Duolingo, we take a different approach—one that eliminates these risks entirely while ensuring a smooth, stress-free experience for honest test takers.
How DET security measures eliminate blind spots
Unlike test centers, which rely on a single proctor monitoring multiple test takers in real time, the DET removes opportunities for human error, bias, or misconduct by combining AI-powered monitoring, multi-camera verification, and post-test human review.
Here’s how we make cheating nearly impossible:
🔒 Two-camera system provides a comprehensive view
Traditional test centers often rely on a single proctor's line of sight, but the DET’s dual-camera system ensures a complete view of the test-taking environment:
- Primary camera (computer webcam): Captures the test taker’s face and upper body.
- Secondary camera (smartphone): Provides a clear view of the screen, keyboard, and surrounding area.
With both views recorded, there are no blind spots—test takers cannot look at hidden notes, use another device, or receive outside help without detection.
🔒 AI-powered monitoring works in the background
Unlike human proctors who may be distracted or biased, DET security measures analyze every test session consistently and objectively in real time, flagging anything unusual:
- AI analyzes typing patterns to detect if someone is copying text instead of composing naturally.
- Screen recording ensures that no unauthorized programs, notes, or browser tabs are opened.
- AI flags unusual pauses or rapid typing shifts, helping human proctors focus on reviewing potential misconduct.
For most test takers, this all happens seamlessly in the background—there’s no disruption to the test experience, just peace of mind knowing their score will be fairly certified.
🔒 Anonymous proctors and post-test review prevent interference
One of the biggest security flaws in test centers is the potential for proctors to be influenced, bribed, or involved in misconduct. The DET eliminates this risk entirely by randomly assigning test sessions to proctors, and keeping those proctors anonymous from test takers.
- Proctors never interact with test takers. Unlike test centers, where proctors supervise in real time, DET proctors review test sessions only after they are completed.
- Test takers cannot bribe, persuade, or pressure a proctor. Since proctors do not observe live exams and have no direct contact with test takers, there is no opportunity for manipulation.
- Every session is recorded and reviewed objectively. AI flags potential violations, and proctors conduct thorough post-test reviews to ensure all rules were followed before certifying a score.
By eliminating both proctor bias and the possibility of misconduct, the DET ensures that every test is judged solely on merit, creating a fairer and more secure testing experience for all.
A new standard for test security
Traditional test centers are far from foolproof—and as technology evolves, so do the methods that people use to cheat. The Duolingo English Test (DET) isn’t just designed to match test center security; it’s designed to surpass it, creating a fairer, more reliable testing experience for all.
By leveraging:
- A two-camera system to ensure complete test session visibility
- AI-driven keystroke tracking to detect unnatural typing patterns
- Screen recording to prevent unauthorized browsing or external assistance
- Anonymous proctors who review tests after completion
- AI-human collaboration for precise, unbiased security enforcement
... the DET makes cheating far more difficult than any in-person test—while ensuring honest test takers receive a certified, secure score.
With security measures working seamlessly in the background, test takers can focus on showcasing their English skills—knowing that their results will be fair, trusted, and protected.