Prompt and punishment: 50% of SNU students in coding course penalized for AI use

The fastest way to finish an assignment turned out to be the fastest way to lose points.

Thirty-six of the 62 students enrolled in a fourth-year computer engineering course during the first semester of the 2026 academic year were penalized for using AI to complete their assignments, according to a Seoul National University (SNU) representative on Thursday.

The course focuses on the principles, implementation and operation of computer networking and requires students to code for their assignments.

“All course activities will be conducted without the use of generative AI to foster students’ problem-solving and critical thinking skills,” the course syllabus reads.

But Park Kyoung-soo, the class’s professor and member of SNU’s Department of Computer Science and Engineering, began noticing suspicious patterns in the students’ assignments.

“I asked students who had used AI [in their work] to come forward voluntarily,” he said. “I then interviewed every student in the class at the end of the semester and identified others who had used AI.”

Park gave zeros on the affected assignments to the 25 students who had voluntarily disclosed their use of AI. He gave the 11 students who only later confessed to using AI during their meeting a final grade of D minus for the entire course. In other words, students who came forward willingly received zeros only on the assignments for which they used AI, and those who failed to come forward faced a cap on their overall grade for the class.

Some of the penalized students reportedly used AI on two or more of the course’s four assignments.

“Some assignments suspected of involving AI contained code that neither [I] nor the teaching assistants could understand,” Park said. “In some cases, the students themselves were unable to explain the code that [they had supposedly created].”

Entering the same assignment prompt into an AI chatbot reportedly produced code similar to what some students submitted.

After more than half the class was penalized, the department’s student government submitted a letter of protest to Park.

The student representatives argued that the criteria to determine whether a student had used AI was unclear.

“Students who did not use AI may have been wrongfully penalized because human-written code can resemble AI-generated [ones],” said a student representative of the department’s student government.

However, Park rejected the student government’s claim.

“All 36 students who we identified ultimately admitted to using AI in their assignments,” he said.

He also warned that students who submit AI-generated code without understanding the underlying principles lose much of the course’s educational value.

“If students simply follow AI-generated answers without understanding what code to use, where to use it or why, they won’t be able to recognize when AI makes mistakes,” Park said. “Using AI when appropriate can be beneficial, but relying on it indiscriminately causes students to miss valuable learning opportunities.”

Regarded as one of the most prestigious universities in the country, SNU has faced repeated controversies over the misuse of AI since last year.

The university ordered that students retake an experimental statistics exam after some were caught using AI in October 2025. A similar incident occurred two months later, when students used AI for an online exam for an earth and environmental change course. The instructor scrapped the test and replaced it with an assignment.

The university introduced its official SNU AI Guidelines in March to establish campuswide rules for AI use. The latest incident marks another large-scale case of AI misuse despite those guidelines.

BY LEE GYU-RIM [lee.jiwon10@joongang.co.kr]