The College Hill Yoga classes are set up so that everyone begins in the Introductory classes. Students should take a least one session of the Introductory class before moving on to the next level.
Students should start out in the Introductory class because in those classes we learn some preliminary actions that are necessary for the higher levels. Without these preliminary actions the topics covered in the higher levels will be lost on the student.
Students who have done other forms of yoga, but do not have any experience with Iyengar Yoga, should also start out in the Introductory class. This seems to be a sticking point with people who have experience in another style of yoga. They don’t consider themselves to be a “beginner” so they think they should not have to be subjected to what they think will be an “easy” class. In the Introductory class the poses are more simple but the class is not necessarily easy. You still have to pay attention, listen to the teaching and try to translate what you are hearing into actions within your own body.
The truth is that other styles of yoga are not the same as Iyengar Yoga. The instructions given in an Iyengar Yoga class are quite different than what is being taught outside the method. They are really not comparable.
Here’s a post from last year that covers a similar topic: What does it mean to “learn yoga?”