Because It Does Not Even Receive the Desired Affect Exams don't show what a student has learned, and most certainly help with the retention of the knowledge. Also, what type of message does that send - you can pass in life if you pull a few all nighters cramming? Exams do nothing but stress out students with enough on their plates already. If school systems really cared about the students, they would abolish these tests in favour of monthly or bi-monthly culminating tests, covering everything learned that unit. IF this were the case, minimal studying would be needed as well, because a lot would be gone over in class, repeatedly, with later units drawing on earlier ones. Or something such as that.