I have found the need to change student groups on occassionally. I agree with the module and try not to, but sometimes it is best for everyone. I find simply exchanging a few students here or there can make them stand out as a troublemaker and does not work well. I completetly redefine all groups with all students. This puts everyone on an even playing field and seems to work well.

Agreed. There is no disputing the importance of planning and preperation. The instructor must know the course better than the student. One must still keep in mind that continueous updating and refining is essential as well. Without doing this, the course will become a dinasoar.