At the beginning of the day, tell the class that you have secretly selected a pupil whose behaviour is going to be a special focus for the day. If at the end of the day the selected pupil has made good choices, the entire class will receive a reward like a quick dance to a song or a similar fun activity (heads down thumbs up perhaps?).
If the child does well, they are also named and praised in front of the class.
However, if the pupil has not made good choices, then the class does not receive an award. In this situation the child is NOT named.
Whether or not the teacher really does select a specific pupil at the start of the day is of course down to the conscience of the individual practitioner….