I guess the first question we must ask is, “What defines effective Sunday School teaching?” If we asked 100 different people, we would probably get 100 slightly different answers. I would imagine for most of us though, we would consider ourselves effective if we made a positive difference in the spiritual foundation building of our students.
We sometime allow ourselves to forget the purposes of Sunday School (or any Bible class for that matter). Initially, Sunday School was created (educated guess, I grant you) to assist parents in teaching their children about God and what He wanted for them and from them. It was an opportunity to reinforce what the parents were already teaching at home. If done really well, it also provided additional practice in Christian Life Skills, teaching areas of the Bible not yet taught at home and more.