Near the end of December, 2000, I was sat in the staffroom listening to my head of department speak. After he had finished his introduction, he invited me up to the front where he produced a flak jacket which he insisted I wear before handing me a plank of wood with a large nail driven through it. I would need these at my new school, he explained.

I was moving to a school with a bad reputation in order to take up the post of second in science. I wanted to make a difference – I think we all do – but some colleagues had strongly counselled me against the move, suggesting that it was a bridge too far.

A term after I joined my new school, at the age of 25, I found myself head of science following the departure of the previous one. I had to manage a daily draft of science supply teachers because we were never fully staffed; once, I had to send one home because he smelled of alcohol. My school’s reputation meant that it was hard to get good teachers to work there. That was the kind of situation we were dealing with.

Not only was behaviour extremely challenging, at times it was unsafe. I had a lab on the ground floor with a door one side and a fire escape door the other. One student who never seemed to go to lessons would interrupt mine by opening the door and shouting, “Where’s that brer?” On one occasion, I opened the fire escape door, probably to ask some students outside to go to their lesson, when a heavy iron retort stand missed my head by a few centimetres. It had been thrown out of the window of the lab above.

I remember teaching a lesson about the kidneys in which I turned around to indicate to the class where they are located. One student – let’s call him Jack – shouted out, “We don’t want to see your fat arse!” When I reported this to my line manager, he commented, “Oh, Jack will be fine once he gets to know you. And anyway, I wouldn’t describe your arse as fat; I would say it’s quite pert.” – this was clearly a very long time ago. Needless to say, nothing ever came of the incident just as nothing ever came of the time when a child in a balaclava threw a lump of ice at one of my teachers.

In those days, I would have appreciated a reporter writing a piece on the school and how it was failing its students, the vast majority of whom just wanted to learn – were desperate to learn – but who were not being provided with the right environment in which to do so. An article in the local paper might have acted as a circuit breaker, forcing the school to make changes. But there never seems to be any interest in such stories. A school quietly gains a poor reputation and middle class parents figure out that it’s best to send their own kids to the school down the road. That is that.

Nevertheless, over time my school gradually improved. I argued strongly for a tougher and more coherent discipline policy. We gained a new headteacher and the school was rebuilt under the private finance initiative, one result of this being a site that was far easier to manage. We set-up senior staff patrols during lesson times – “Is everything to your satisfaction, Miss Brown?” – and a centralised detention system. Any student who refused to attend detention would be picked-up and escorted to see the headteacher by one of the assistant headteachers. By this stage, I was an assistant headteacher and so I was involved in the process, as I was with the limited number of students who we ultimately excluded for violent or persistently disruptive behaviour.

It was far from a ‘no excuses’ system but it was much improved from when I first started working there. We seemed better able to recruit and retain good staff and this was probably because of the behaviour policy. And improvements showed in a rise in Key Stage Three results – before these tests were abolished – and in GCSE results. I cannot prove it but I am personally convinced that these gains were due to the tightened behaviour policy; teaching methods hardly changed the whole time I was there.

This is not just meaningless data. This is not evidence that you can dismiss as ‘neoliberal performativity’. These were real kids with ambitions and hopes whose prospects were better because of what we had achieved. Those children who were desperate to learn were now receiving more of what they deserved; quality teaching in lessons with far less disruption.

That is why I am wary of hate campaigns against schools that attempt to improve behaviour. You read some pretty lurid stuff on Twitter and I certainly don’t agree with every policy I read about. However, I have learnt to be cautious. On investigating one claim that a school was forcing students to wear signs around their necks to shame them for not having correct uniform, I discovered that the truth was a little different; once a student had been spoken to about uniform, they were given a lanyard to wear in order to prevent every other members of staff from hassling them about it. This is nothing other than a perfectly rational way to manage the situation.

Yet there are plenty of armchair warriors lining up to condemn schools, and headteachers in particular, for strengthening their behaviour policies. Often, these commentators haven’t taught for as much as five minutes in a challenging school or are people who have moved on from teaching. They delight in explaining how personally rebellious they are – oh, please – and, at their very worst, they throw around Nazi jibes.

I have a challenge for these critics. They should get together and try and turn around a tough school themselves. They can deploy their ideologies as they see fit, putting them to the test. And we will all watch from the sidelines and judge their efforts.