The number of pupils being excluded for bad behaviour in Scottish schools has increased in the last year.
Exclusions have risen each year since 2002/03
A report said overall exclusions had risen by 4% in 2006/07 to 44,794.
Schools Minister Maureen Watt said she was "extremely concerned" that exclusions, which she believed should be a last resort, had gone up.
The report also revealed that there was a 14% rise in exclusions due to physical assault, though numbers were a very small proportion of the total.
The Scottish Government has written to umbrella local authority organisation Cosla as part of a review about how statistics on violence in schools are collected.
Ms Watt said it was important to have comprehensive and reliable evidence to inform policy making.
She added: "I firmly believe that where a child is excluded from school we have - collectively - failed that child. Our early intervention policies will help to set children on the path for success, by providing them with the help and support they need."
Tom McGhee is director of Spark of Genius, which provides education for young people excluded from mainstream schooling.
He believed that family breakdown and economic circumstances were among the factors which led to youngsters misbehaving in class.
Mr McGhee added: "Very often the individual child does not have the skills to profit within a mainstream environment.
78% of exclusions were male pupils
32% of exclusions involved general or persistent disobedience
26% of exclusions involved verbal abuse of staff
16% of exclusions involved insolent or offensive abuse
1,210 exclusions from special schools
6,018 exclusions from primary schools
37,566 exclusions from secondary schools
"I think teachers do a really, really good job at keeping 20 pupils happy in the classroom.
"The issue with exclusions is often the barometer of problems. If it becomes a permanent exclusion those children start the slippery slope down."
In 2005/2006, the then Labour/Liberal Democrat administration revealed that there were 42,990 exclusions - which represented an increase of 2% on the previous year's figures.
Exclusions have risen each year since 2002/03, when the figure stood at 37,442.
The director of The Prince's Trust Scotland, Geraldine Gammell, said that increased levels of school exclusions were largely preventable.
She added: "Greater investment in early intervention and alternative learning programmes, which are individually tailored and targeted to the needs of those young people most at risk, will prevent them moving into a life of unemployment and potentially into the criminal justice system.
"This ultimately results in them making a worthy contribution to our economy and society."
Scottish Conservative MSP Liz Smith said the figures were deeply worrying.
She added: "When it comes to tackling persistent offenders, there has to be a much stronger line.
"It simply isn't acceptable that these pupils are allowed to remain in mainstream classes disrupting the education of the well-behaved majority and making life a misery for their teachers."