Zero tolerance of bad behaviour is one of the secrets of Kingswood high school's success in turning itself round.
If a pupil at the Hull school talks over the teacher, the teacher continues with the lesson but writes their name on the board. If they carry on a tick is placed beside their name indicating a 10-minute detention.
If they persist a second tick leads to a half-hour detention. A third tick prompts a call to the student liaison officer who will come and remove that child from the class, returning them at the end when other pupils have gone, to talk to the teacher.
Loz Wilson, deputy head of Kingswood comprehensive, the worst performing in the country just four years ago, said: "If there is no system for removing children then schools have a real problem. We don't let anything go. We operate a zero-tolerance policy. We follow everything up.
"If a child refuses to sit properly in their chair or take their jacket off, we take issue even with that."
Four years ago only 2.7 per cent of Kingswood's pupils achieved five GCSE passes and pupils rampaged down the corridors when they should have been in class. Youths from the local Bransholme estate, the largest council estate in western Europe, were also breaking in and disrupting lessons.
Mr Wilson said: "We were spending so much time dealing with disruption we were not getting anything else done."
Last year, however, the school sailed through inspection with flying colours and 28 per cent of its 1,090 pupils gained five GCSE passes. This year 35 per cent are expected to do so.
The turning point came when staff decided to concentrate on the quality of teaching and learning, rather than behaviour.
Mr Wilson said: "We decided to look at those areas of the curriculum where we were engaging students and there was least disruption and started to model good practice."
In addition, full-time cover staff were employed to avoid the instability caused by using supply teachers and full-time "student liaison officers" were appointed to remove disruptive pupils from classes.