UNAM to retest up to 58,000 applicants after online exam concerns

In short: UNAM says up to about 58,000 applicants may have to take a new in-person entrance exam after its first fully remote test produced unusually high scores.

What happened

Earlier this summer, nearly 160,000 people took the entrance exam for UNAM, Mexico’s largest university. For the first time, UNAM ran the exam fully online over several weeks, using a “lockdown” browser and webcam monitoring that used AI (software that tries to spot patterns, like a security guard that watches many screens at once).

When results came back, top scores jumped far above past years. From 2021 to 2025, about 3.5 percent of test takers scored 100 or more out of 120 questions. This year, about 16.3 percent did, roughly a fivefold increase. Scores of 110 or more also rose from about 0.9 percent in past years to 5.5 percent.

Those numbers led to accusations of widespread cheating. UNAM appointed an expert commission, which recommended a “control exam,” meaning another test taken in person. The retest would apply not only to students who got in based on this year’s scores, but also to anyone who would have qualified under the minimum score cutoffs used since 2021. UNAM’s rector apologized to honest applicants and said the new exam is needed to ensure fairness.

Why it matters

This case shows a practical problem with remote, AI-supervised testing. Even with tools meant to block web browsing and flag suspicious behavior, a school may still struggle to trust the results. For students and families, the stakes are immediate, admission decisions could change, and many people may need to prepare for another high-pressure exam on short notice.

Source: Arstechnica