Depends on the class, but size starts at around 60 and within 2 weeks is at around 30 due to natural attrition in first term classes. No there is no option of doing extra credit or grading for a portion of the class that is not a graded element. In one of the schools I work for there is no leverage for the instructor, which minimizes the work of the students who are conscientious - though this is just my personal opinion [based on being in this business for over20 years]. Students need to be challenged and held accountable, or they tend to fall into old patterns of not putting school high on the list of important things to get done.