A top Mexican university used AI to prevent exam cheating. Now thousands of admissions are in doubt

By Mauricio Torres, CNN

(CNN) — Daniel Fernando García Velázquez took the admissions exam for Mexico’s most famous university four times before finally getting the result that should have guaranteed him admission.

On his first three attempts, he had no option other than to travel the 400 km (250 miles) from his native Veracruz to Mexico City to take the test, because the prestigious National Autonomous University of Mexico (UNAM) insisted it had to be taken in person.

On his fourth – and what should have been victorious – attempt this June, he traveled up anyway, even though this time, for the first time in the university’s history, it would be administered online.

This time, Velázquez aced the exam – scoring 94 out of 120 in what should have secured him a spot on the Communication and Journalism degree program offered at UNAM’s Aragón School of Higher Studies.

Yet, despite that result, Velázquez doesn’t know if he will be allowed to attend the new semester that starts on August 10, because UNAM has suspended enrolment while it deals with a scandal over suspected widespread cheating.

UNAM annulled thousands of tests after results showed an unusually high number of perfect scores, suggesting some students cheated either through using artificial intelligence tools or by obtaining the questions in advance. While just around 3,000 of the 150,000 or so tests have been invalidated, all students – including those who, like Velázquez, are not suspected of cheating – have been left in limbo pending the result of UNAM’s investigation into the matter.

Compounding UNAM’s headache is that many of those students who feel unfairly treated are now blaming the AI surveillance system that was supposed to ensure the exam was cheat-proof.

The resulting uproar has reached the highest level of politics, with Mexican President Claudia Sheinbaum — herself a UNAM physics graduate — suggesting on Tuesday that the university enlist the help of the attorney general to get to the bottom of the matter.

A symbol of contemporary Mexico

UNAM’s history traces back to the 16th century, when the government established what was then called the Royal and Pontifical University of Mexico. It was granted autonomy in 1929 and since then has become a symbol of contemporary Mexico, a center for political and social movements and a platform for social mobility in a country where private higher education is prohibitively expensive for many.

As a result, competition for its places is fierce. Every year, more than 100,000 applicants apply for entry and usually between 80% and 90% are rejected. Its undergraduate admissions exam has 120 questions, and the number required to pass varies depending on the demand for each subject, with Medicine often setting the highest bar due to its popularity.

The university’s stringent entry criteria often leads to protests demanding it provide more spaces in its classrooms.

UNAM had hoped that its decision to administer the test online this year would make the test more accessible and equitable to students, as they would not have to travel from across the country to the test sites, which are mainly in Mexico City and surrounding areas.

To safeguard against cheating, it said a system based on artificial intelligence would “allow for the capture and recording of any behavior and action carried out by each applicant” and this would be used in support of human monitors.

What went wrong?

More than 150,000 people across Mexico took this year’s test, which was set on weekends during both May and June, competing for just 21,962 available spots.

One month later, just before the results were due to be released, UNAM made a surprise announcement: two percent of the tests — around 3,000 — had been invalidated due to the detection of “behaviors contrary to what is established in the Call for Applications and in University Legislation.”

At the time, it gave no further details. However, it has since emerged that the results showed an unusually high number of tests with perfect scores, suggesting that some students may have cheated using artificial intelligence tools or by obtaining the questions in advance.

“It’s really shocking because of the number of students who got a perfect score on the exam, something we hadn’t seen before; the number has tripled compared to previous years,” said Alma Maldonado, a member of the technical commission appointed to investigate the situation, in an interview with CNN’s Perspectivas program.

“Also, the number of students who didn’t get any correct answers or only got one or two correct also went up, which raises a lot of suspicion.”

Meanwhile, there has been a slew of viral videos on TikTok and other social media platforms in which users allegedly show how to trick the monitoring systems for the exam.

Daniel Flores Miranda, another young man who took the exam, told CNN that an acquaintance offered him a computer program that would solve the test for him.

He said the cost was 2,500 pesos, about US$150, and though he did not use it, he knew of people who did and passed.

What happens next?

Territorium Life, the company contracted by UNAM to administer the exam, has defended its surveillance systems amid complaints by some students that there was too great a reliance on AI and not enough on human monitors.

In the letter to the technical commission, it said its platform “operated as planned” and that its integrity “does not depend solely on technological infrastructure. It requires the coordination of two inseparable components: technological security and academic security.”

For would-be students, it remains unclear exactly who will be allowed to take their seats in August.

On Friday, UNAM said it had received the results of the commission’s investigation and that it had found that some entrants had cheated by using phones, companions and even identity theft during the exam.

Consequently, it said it would administer a control exam — this time, in person — to all applicants who got a mark sufficient to pass either this year or for the past five years, equivalent to around 58,000 applicants.

The dates and locations of the makeup exam have not been released, though the committee recommended it be held “as soon as possible” to minimize disruption to the semester.

UNAM’s Rector Leonardo Lomelí has called for all applicants this time round to show “ethical behavior.”

“Plotting not only harms the institution, it harms society as a whole, it erodes the social fabric, it is a practice that we must eradicate,” he said.

Mario González collaborated with this report

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