The kids should be lined up. They should not be talking out. You want a school that teaches discipline and confidence. The instructor should be strict but not abusive. At my school, I have the kids do knuckle push-ups when they get out of line.
Some instructors smack kids around and get in their face.
I don't agree with that. You have to stress discipline, but you can't go overboard. When you go to a new school, you should be able to watch a class. If they will not let you watch an entire class, go to another school. If an instructor has a good attitude, the students will, too.