Life is full of threes. There are three blind mice, three musketeers, three bears and three wishes from the genie. There are also three colours on a plethora of nations’ flags, while three is a number of significance in religion, too - the Holy Trinity in Christianity being a good example.

Is it any wonder, then, that the “three-strikes” rule in behaviour management is so ubiquitous in education? It can often seem as though there is hardly a teacher who doesn’t give their students three chances before laying down punishment. Three, it seems, is the go-to number, a way of providing some standardisation in behaviour policy.

Yet when I was a primary teacher I was never really aware of the power of three. I didn’t give three chances; I had my baseline “Do your best and be the best you can be”, and if someone “forgot” their behaviour I gave them an opportunity to make it right. For most children this worked: we had a mutual understanding and tried hard together in class to be a team, with agreed expectations and children having ownership of the rules they had established.

It wasn’t until I became a supply teacher that I came across the “three strikes and you’re out” rule. I was asked to use this method as it was the approach being employed consistently across every classroom. It presented me with a challenge: what constituted a strike in this class and for my teaching, and how did that compare with the practice of other classes and teachers in the school?

There was nothing written down to refer to, so I applied my own thinking to the standard of behaviour I deemed acceptable, recognising that I was new to this group of children, that we did not know each other and had not had time to build up the same kind of relationship I had established with the students in my own classroom.

The first child to accumulate the three strikes protested, cried and then promised to be good if I let him stay in the classroom. I stuck to my guns and sent him out. The policy said you should do so and it gave the wrong message to go back on the threats made.

But then, five minutes later, the child was sent back to me with a note from another teacher saying that in order to send out a student their behaviour should be really unacceptable, much worse than I had assumed.

Three strikes, then, was clearly not the “universal” policy it was described as. It was an illusion of standardisation. In reality, levels of behaviour were still being judged by each individual teacher in their own classroom.

There was also the problem of the children treating it as a game. Some students want to get sent out of the classroom so they don’t have to do the work, and they do their best to get three strikes as quickly as possible.

Jock Mackenzie, a retired American teacher who is now an education blogger and speaker, tried to get around the problem by changing tack slightly (he details his methodology here: bit.lyMackenzieBlog). He uses the three- strikes rule but it is three strikes and you’re in, not out. The “in” means different things - in after class, in trouble, in to carry on with work and so on.

However, whether this alternative approach is successful or not, the three-strikes policy still raises an important question: does the number of warnings really matter or should we instead focus on the way in which behaviour is established and maintained within the classroom? Does using a number in fact make it into a game in which children are rarely the winners?

For me, the three-strikes rule abrogates my own value system for the alleged good of the institutional whole. It also potentially teaches students the wrong lessons about behaviour. Arguably, children may learn that it is acceptable to misbehave three times before it becomes serious and there are consequences.

I wouldn’t advocate a standardised rule for any number of strikes. Instead, set expectations high and give children ownership and responsibility and they may not need three chances to avoid being sent out.

Fiona Shelton is senior lecturer in education studies and postgraduate studies at the University of Derby.

In short

The rule of three is established in many areas, in everything from fiction and fable to flag design.

In education, the power of three has seeped into behaviour management, with what seems like the majority of schools insisting on a universal “three strikes and you’re out” policy.

This is problematic - it supersedes a teacher’s own approach and gives the misleading impression that behaviour management techniques are standardised when they are not.

It also gives children the wrong impression. It enables them to manipulate behaviour management and suggests that they will always get three opportunities to misbehave before being punished.

It is much better not to give set numbers of warnings but instead to deal with children on a case-by-case basis.