Roberto Serrano, a Brown University economics professor, gave a take-home midterm and it seems most of the students used AI handle the work. Suspicious of cheating, Serrano required the final exam to be taken in-person. For Inside Higher Ed, Emma Whitford charted the discrepancy between high midterm marks against much lower final marks:

Education needs to figure out new ways to grade progress, and students need to figure out how to think deeply for themselves. Unless you’re student number one, in which case you may carry on.
Visualize This: The FlowingData Guide to Design, Visualization, and Statistics (2nd Edition)
