[vlovich123]

Did the cohort due poorly or were the tests given to that cohort harder than in previous years? Or was the teacher a more difficult grader than others? You're jumping to the conclusion that the cohort was underperforming just because the grades were lower when other things out of their control could have been involved.

[airstrike]

Tests are generally almost identical YoY where as humans are all very different! I think I'm making the simpler argument here

[vlovich123]

The university I went to had student run test banks of previous exams that the administration sanctioned. If the following year you get the same question as the previous year, then you’re going to do better than the year that got the first version of that question.

You’re also ignoring the human element of grading particularly in subjective parts of an exam.