Developmentally, preschoolers are not ready for long sentences or big words. Neither can the list of behavioral expectations contain many items. A good rule of thumb is three- or four-word rules and a list three or four rules long. Be sure this list is posted prominently in every room the children are in for any length of time throughout the day. Because preschoolers cannot read, the list must be clarified verbally and reinforced constantly.
Clear rules alone are not enough. Preschoolers need an equally clear understanding of consequences -- what will happen should they disobey. Having clearly defined consequences, however, will prove effective only if the teacher is consistent in enforcing those consequences.
Essential to preschool classroom management are daily lesson and activity plans that fit the children's developmental needs and attention spans. Younger preschoolers cannot be expected to sit quietly and listen for much longer than the length of a storybook. Even then, such stories need to be active and engaging, involving the children and allowing them to move a bit. Older preschoolers, 4- and 5-year-olds, can sit relatively still and listen for closer to 10 or even 15 minutes. A savvy teacher will plan carefully to minimize rule violations and behavior problems by playing to the strengths of her pupils with developmental sensitivity and aplomb.
Perhaps the single most important lesson a preschool instructor can teach is that aggressive behavior is never acceptable. Preschoolers must learn to use words to solve conflicts rather than aggressive actions. Even though aggressive pupil behavior can rattle a teacher, he mustn't show that he is rattled, and even more importantly, he mustn't use aggressive behavior to stifle aggressive behavior. He must defuse the volatile situation swiftly and calmly, address the behavior problem and enact the previously articulated consequence.