By giving you threads, you mean some threads to start branching ideas from :? haha
Well, you can talk about how examinations are tasking on people's mind. They make people nervous about showing how well they can do on the exam, resulting in panicked performance during the exam. Other things for bad effects: lack of accuracy because (most) exams can't test what a person truly knows. They can only sample. Therefore, people will cram and not really learn for the sake of learning, therefore making their education a pointless series of cram sessions- This is bad because it's unproductive in the long run~
Now for the good job on the evaluation: exams are meant to sample knowledge, as said earlier. They place everyone on the same standard for comparison. Er. Stuff happens. (though this does not answer about the good of the test, tests can also remind people of their mistakes if they (can) go back and check where they went amiss.
Opinion: "YOUR opinion here" What do you think? Do you think tests and exams are worth it? Do they really show you what you know/don't know? Or even take a middle path!