I think I know where you are coming from, sunpainter: but when you say "simple", you seem to conflate "simple" learning and teaching approaches and "simple" behaviour management expectations. I would suggest that management expectations should always be simple and then consistently enforced through appropriate praise and sanctions. You can easily have a very complex, interactive lesson that keeps the kids motivated and engaged, and manage it using very simple behaviour expectations consistently enforced. Of course, there are times when a "simple" teaching and learning activity may be appropriate, such as last period on a Friday or just after PE: but the aim should be to motivate and interest children at all times (let's forget about the red herring of "fun" for the moment). As for keeping it "dull" for those who misbehave: how do your children behave when they are bored by doing something "dull", such as sitting in the back of a car on a long journey? Are they fractious? fidgety? bad tempered? I wonder why we would want to recreate those feelings in a classroom, especially in those pupils who are likely to give us the most trouble? And when our children are stuck in the back of a car on a long, dull journey, don't we try to find ways to keep them interested? So why shouldn't we do that in classes too? Seems basic psychology to me.