Which method of instruction do you recommend for groups larger than 40 students?

How often should an instructor do in-serice training?

How do you handle a situation when you have a student who does his or her best but continually shows signs of extreme weaknesses in a course? What can you do or say not to hurt that student?

As an instructor, how do you manage or deal with a student who wants to dominate every discussion and answer every question that you have presented?