Although students have three weeks to add courses, they must keep up with the work. They should not fail to hand in assignments in all the courses they are considering. Taking three weeks to decide on courses and only then beginning all the work for their courses sets the table for a very bad meal. Adding courses after the third week is almost impossible; too much has happened. The student will never catch up.
Cornell students have three weeks to add courses. The idea is to encourage them to "shop" among six or seven possible courses for the four or five they will actually take. Shopping includes checking out the syllabus and the instructor. It also includes (although many students neglect this step) browsing among the books assigned for courses they are considering. Students spend much more time studying for a class than they spend in a class; they should be interested in the books they will be spending much time with. In fact, we often urge students to wander around the bookstore and notice which courses require books that most interest them.
Unlike in high school, dropping a course in college is often sensible and never a disgrace. The college encourages the practice by allowing half the semester – seven weeks – to drop without penalty. The idea is to allow students to try perhaps more difficult or a greater number of courses than conservatively prudent and to be able to adjust their workload to a beneficial and reasonable level if necessary.