Another annual rise in the number of pupils excluded from Scottish schools is a troubling statistic, but what is most alarming about the figures issued yesterday is the nature and level of disruption endured daily by many teachers and children. It goes without saying that physical assaults (with or without weapons), verbal abuse, threats of violence, fire-raising, damage to property and other offensive behaviour are absolutely unacceptable. That there were more than 7000 physical assaults (10% of them incorporating an improvised weapon) in Scottish schools in 2006-7 is shocking. Such behaviour should never be tolerated, but by far the most common reason for removing pupils is general or persistent disobedience. That raises the deeper question of how to deal with increasing levels of routine disruption to classes, which wears down teachers and prevents children who want to learn from doing so.

Another annual rise in the number of pupils excluded from Scottish schools is a troubling statistic, but what is most alarming about the figures issued yesterday is the nature and level of disruption endured daily by many teachers and children. It goes without saying that physical assaults (with or without weapons), verbal abuse, threats of violence, fire-raising, damage to property and other offensive behaviour are absolutely unacceptable. That there were more than 7000 physical assaults (10% of them incorporating an improvised weapon) in Scottish schools in 2006-7 is shocking. Such behaviour should never be tolerated, but by far the most common reason for removing pupils is general or persistent disobedience. That raises the deeper question of how to deal with increasing levels of routine disruption to classes, which wears down teachers and prevents children who want to learn from doing so.

If there is a glimmer of hope in these statistics, it is that almost all exclusions were temporary and lasted an average of three days. Exclusion can be a useful sanction in bringing home to pupils and their parents that they have breached the bounds of acceptable behaviour, but applied without proper consideration is more likely to compound the bad behaviour of persistently troublesome pupils and can lead to the unhelpful situation of children moving from school to school without the root cause of the problem being tackled. Maureen Watt, the Schools Minister, believes that exclusions represent a failure of the system. That is true in that violent and aggressive children are not having their needs met, but if, as she would like, exclusion is to be a last resort, there must be effective intermediate measures. The enormous variation in exclusion rates - the rate in Glasgow is 10 times that in Orkney - reflects social conditions as much as discipline. It gives credence to the argument of the Scottish Secondary Teachers Association that the increasing number of exclusions reflects what is happening in society. Its general secretary, David Eaglesham, is right to say we need radical solutions to deal with problems in children's behaviour before they get to school, but that does not mean that schools should not also be part of a package to tackle those problems. Teachers are not social workers, but education as a universal public service for children has a unique role in their development.

Children from poor and troubled backgrounds (especially those in care) feature disproportionately in the exclusion statistics. That is not new, but what is truly disheartening is that, despite a number of innovative programmes which have interrupted effectively the cycle of neglect and poor care at home leading to difficulties at school and violent behaviour, they have yet to be widely implemented.

No teacher should have to face verbal or physical abuse or threats of violence at work. No pupil should fear going to school or have their lessons disrupted by others' bad behaviour, but it is only when the troublemakers see education as meaningful that they will want to be included rather than excluded.