Gotta disagree wholeheartedly with you there. If I have one big exam at the end, I will procrastinate and likely end up doing poorly. Instead, in my medical school, we are quizzed at least once a week - this week alone I have 2 quizzes and 2 tests. I failed yesterday's quiz, as I knew I would since was at a wedding on the weekend. But I will know the material for the test on Friday, and now I know what kind of questions to expect.
Weekly testing lets me figure out how I'm progressing, whether or not my study habits are working, and also provides a significant amount of opportunities to do well - that quiz I failed yesterday really does not in anyway hinder me from acing the course.