Study as long as it takes to master the material. For some classes, that means five or six hours a week; other classes may require 15 eye-ball-popping hours or more each week. It totally depends on your noggin, the course, and the test.
Have you heard the tried old nugget; “study two or three hours outside of class for each hour in class”? That is utter codswollop … no, I mean it, codswollop! Can you imagine a carpenter saying, “A cabinet takes eight hours to build.” and then he stops after eight hours, whether the cabinet is complete or not? It ain’t finished ’til it’s finished. Might take four hours. Might take forty.
You must, however, be strategical. Undoubtedly, you have other classes to study for. You (hopefully) have a social life to maintain … I mean, those orcs ain’t gonna kill themselves. You may even have (the Lord between us and evil) a JOB! You’ll have to make a judgement call about just how much time any particular class is worth. You may decide to study 10 hours a week and take the B rather than 30 hours to get the A. Whatever the case, don’t let it just happen to you. You make the decision and spend your time and energy accordingly.
Updated from Sept. 2008 post