Earlier this summer, nearly 160,000 applicants took the entrance exam for UNAM, Mexico’s largest university. For the first time, they did it completely remotely, using a “lockdown” browser and AI-powered webcam proctoring software, over several weeks from late May through early June.
When exam results came in, they bore little resemblance to past results, especially at the top. Between 2021 and 2025, 3.5 percent of test takers scored 100 or more on the 120-question UNAM test. This year, 16.3 percent did so.
The story was even worse at the highest of the high end. Between 2021 and 2025, 0.9 percent of test takers scored 110 or more; this year, 5.5 percent did so.
The surge in top scores led to accusations of widespread cheating, and UNAM appointed a commission of experts to investigate the situation.
The group was given the unwieldy name “la Comisión Técnica de Personas Expertas para la Revisión del Proceso de Selección de Ingreso a Licenciatura para el Ciclo Escolar 2026-2027/1,” and it has just submitted its recommendations. The commission believes that the best path forward, given all the concerns, is to administer a “control exam”—that is, applicants will have to sit for another test, and they will do so in person.
This control exam will apply not only to those who secured a spot at UNAM based on this year’s test but also to everyone who would have been admitted based on minimum successful scores in their program of study since 2021. About 58,000 people could be affected, and places at UNAM will now depend on the results of the new test. (Details on the control exam should appear soon; classes are currently scheduled to begin on August 10, so everything will have to move quickly unless the school decides to delay classes.)
According to Gaceta UNAM, the school’s official news publication, the university rector has apologized to honest applicants, since they will now have to prepare for and take the test again despite doing nothing wrong. Still, the control exam is “necessary to give certainty and guarantee equity in access,” the rector added.
No one yet knows what kinds of cheating may have taken place. The exam was multiple choice rather than essay-based, so it is difficult to look for typical indications of AI cheating (complete answers being pasted immediately into text boxes, etc.). It is also possible that students relied on cheat sheets, leaked questions, and other traditional cheating methods.
A New York Times report last week on the cheating scandal noted that “cheating tips were circulating widely before the tests went live this spring. Online accounts advised students to position monitors outside the web-camera frame where they could access ChatGPT or other AI models. Others suggested hiding earphones under their hair, or hiring someone else to take the exam, off camera.”
Because this year’s exam was administered remotely, applicants had to install and use security products that tried to protect testing integrity. A report in El País said that the test required the LockDown Browser from Respondus. According to the company, once an exam begins in this browser, students are “unable to print, copy, go to other web addresses, or access other applications on the computer. Web searches, instant messaging, minimizing the browser, and hundreds of other functions are also prevented. Once the exam is completed, students are permitted to exit the browser and their computer will return to its normal state.”
UNAM also used a proctoring system from Territorium that monitored each test-taker’s webcam with AI algorithms. The system watched for signs that another person had taken the applicant’s place in front of the computer, or for the use of cell phones or earphones, or even for the applicant leaving the frame. The test also had one human supervisor for every 150 applicants; supervisors received alerts from the system and could notify UNAM officials about irregularities.
These measures do not seem to have worked well. (UNAM canceled nearly 2 percent of total exams for unspecified conduct issues, so it apparently caught a few people.) Even UNAM has acknowledged “the probability that a significant number of applicants may have received help” on the test. AI expert Raul Rojas, speaking to NPR, said statistical modeling suggested “that almost half of the students were cheating when taking the exam online.”
Now, almost 58,000 applicants will have to try again in an official exam room, watched by a human proctor.
