Purdue CS Professor Revisits Argus AI-Cheating Detection Controversy

Summary

A Purdue University CS 240 instructor describes a Spring 2026 academic-integrity controversy involving the use of ChatGPT and other large language models in a C programming course. The syllabus prohibited using AI/LLM software to generate any part of assignments, and the instructor says the restriction was reiterated in at least five lectures. The course also used MOSS for conventional code-similarity cases. A separate tool, Argus, did not contain or train an LLM; it used static analysis to identify unusual source-code indicators that could suggest AI-generated work. Each flag was manually reviewed, and the instructor says 267 of 584 identified students were ultimately flagged, about 45.7%, although not every case was pursued. Argus became usable in mid-March, and an AI Academic Integrity team was formed on March 23. On April 16, 207 currently enrolled students and 60 students who had already dropped were asked to complete a response form by April 20, with nonresponse described as potentially leading to an F and an unfavorable report. Of 117 students who submitted the form before university intervention, 108 accepted responsibility and nine disputed the findings. The process was followed by 144 additional drop requests. University administrators raised concerns about coercion, due process, and the late, retroactive deployment of the tool. The eventual resolution discarded Argus findings from earlier assignments, allowed students who had dropped to re-enroll, and continued using the tool for later work. Seventy-four of the students who initially dropped re-enrolled. The instructor acknowledges that the form should have identified the specific assignments and likely involved individual meetings, and says deployment near the drop deadline was a mistake. The post also reports that students identified as using an LLM performed 10.75% worse on the first midterm and 14.5% worse on the second, while noting that the broader analysis appears in an unpublished SIGCSE 2027 submission. Argus remained in use for the rest of the semester and in later CS 240 offerings.