UNAM's first fully online undergraduate entrance exam for ~160,000 candidates produced a dramatic jump in top scores (3.5% → 16.3%). Despite Respondus and Territorium AI proctoring, multiple cheating methods bypassed controls and UNAM annulled ~3,000 tests while experts estimate nearly half of candidates may have cheated. As a result, roughly 58,000 applicants must retake a supervised in-person control exam, whose results will replace the online scores. The episode highlights limits of current AI proctoring and the need for stronger statistical oversight and operational safeguards.
AI Proctoring Collapse: UNAM Forces 58,000 Applicants To Retake In-Person Entrance Exam
Image: Deposit Photos
Mexico's National Autonomous University (UNAM) has ordered roughly 58,000 applicants to retake its undergraduate entrance exam in person after an unprecedented spike in top scores during its first fully online administration. Historically, 3.5% of applicants scored 100 or higher out of 120; in 2026 that figure leapt to 16.3%. UNAM ran the exam online for about 160,000 candidates, used AI-based proctoring, and then found the score distribution distorted in ways its systems could not reliably explain.
What Went Wrong
UNAM deployed a two-layer security system on paper: Respondus LockDown Browser to block other apps and web access, and Territorium's AI webcam monitoring to flag extra people, visible phones or earphones, and candidates leaving the camera frame. Each flagged session was reviewed by human supervisors who, alarmingly, were asked to monitor roughly 150 applicants at a time.
How Cheating Bypassed Controls
Despite those measures, several methods evaded detection: external monitors running ChatGPT off-camera, micro earphones hidden under hair, full identity substitution, and commercially offered real-time AI answer services. These techniques allowed many candidates to access outside help without triggering the automated flags or human reviewers.
Scale And Evidence
UNAM annulled about 3,000 exams (approximately 2%), but a technical review and public experts said that annulments understated the problem. AI expert Raúl Rojas estimated from statistical patterns that nearly half of the 158,000 candidates may have used some form of cheating. Scores of 110 and above rose from a historical 0.9% to 5.5%, with anomalies concentrated in the top deciles — a pattern consistent with organized, targeted cheating rather than a broad improvement in test-taker ability.
"Almost half of the students were cheating when taking the exam online." — Raúl Rojas, AI expert (reported by The New York Times)
Consequences And Response
UNAM paused admissions, convened its Comisión Técnica de Personas Expertas, filed criminal complaints against companies selling fraudulent exam assistance, and chose a strictly analog remedy: a supervised, in-person control exam conducted with pencils and proctors. Results from the control exam will fully replace the online scores. The new semester begins August 10; specific dates and locations for the control test have not been released.
Who Pays The Price?
The mandatory retake affects both provisionally admitted students and rejected applicants whose online results would have met historical cutoffs, potentially displacing honest candidates who lost places after the curve was inflated. Rector Leonardo Lomelí apologized publicly, calling the retake "necessary to give certainty and guarantee equity in access" to UNAM.
Broader Implications
Coverage of the incident framed it as a landmark AI-era cheating scandal: generative AI and real-time answer services can outpace current proctoring systems at scale, and automated monitoring alone cannot always retroactively identify who cheated. The key takeaway is not that remote exams are impossible, but that deploying AI proctoring without robust statistical oversight, workload limits for human monitors, and layered anti-fraud measures is dangerously optimistic.
What Applicants Should Know: About 58,000 candidates will prepare to retake the exam in person; UNAM will use results from the control exam as the official outcome. The university has pursued legal action against vendors of fraudulent assistance and convened technical experts to guide reforms.
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