There's nothing more discouraging than performing poorly on a test after taking copious notes and studying faithfully for days. Has this happened to you?
It can happen if we don't take notes or study in a productive way. Some methods are just more effective than others, so you should take care to study and prepare for tests in the right way. If you take linear notes and don't number them, for example, and you don't go back and add notations in the margins, you probably won't retain as much material.
And once you take class notes, you must go over them, again and again--but you must do that in an effective way, too. A not-so effective thing to do with your notes is to read over them and highlight. This, alone, will not help you much.
Find out how to avoid the most common study mistakes and you'll soon improve your test performance.