Discipline in school
I think there are two broad categories of disciplinary approach that teachers can follow when facing problematic or bad behaving pupils: casual and severe castigation. A casual punishment, such as a warning, can be used at the first occurrence of misbehavior or for minor offences, whereas severe punishments, such as suspension, should be used when the children recklessly persevere in their misdoings or in case of grave offence.
One advantage of a casual castigation may be that the student has the opportunity to understand what he did wrong, and try to do better, without really going into big trouble. The main disadvantage probably is that such form of discipline may not be enough and may result in the student continuing with his bad behavior. On the other hand, severe punishment make a stronger impression on the student and it also works as a deterrent for the castigated student, who will think it over before doing something bad again, and for the others as well.
If used correctly the different forms of discipline have the right effect of correcting the behavior of the children. However, if sloppy attempts of castigation are used in grave circumstances, the teachers risk losing their control over the students. Vice versa, if severe reprimands follow minor offences, the students may not accept them and complaint about them at home with their parents. And unfortunately, nowadays, it often happens that the parents take the side of their children and blame it on the teachers themselves if the children have or show problems at school, making the role of the teachers even more difficult than it already is.