>In a recent post, Parrhesia suggested that course grades should be 100% determined by performance on a final exam—an exam that could be taken repeatedly, with the last attempt being the course grade
>[...]I suspect this proposal hasn’t seen much contact with people who’ve actually taught classes
This is how a fair number of classes at my university are graded. Particularly math classes are structured so that you could literally ignore the class for 3 months and then just show up and take the exam and that decides 100% of the grade. Some homework is available for bonus points, but it only contributes to going from a failing grade to passing. While retaking the exam to get a higher grade isn't technically part of the system they will let you do it if there is space.
Re-do the exam when it is next offered. The most common math exams (e.g calculus, linear algebra) run 4 times a year so there are quite a lot of opportunities.
>[...]I suspect this proposal hasn’t seen much contact with people who’ve actually taught classes
This is how a fair number of classes at my university are graded. Particularly math classes are structured so that you could literally ignore the class for 3 months and then just show up and take the exam and that decides 100% of the grade. Some homework is available for bonus points, but it only contributes to going from a failing grade to passing. While retaking the exam to get a higher grade isn't technically part of the system they will let you do it if there is space.