Raymond Ross looks at two solutions.
As a former teacher, Jack McConnell, the Education Minister, is only too aware of the acute problems badly behaved children can cause. And with disruptive behaviour on the increase, it is, he says, a "top priority" for him. Hence his setting up last month of a discipline task group to look not so much at "sin bins", as reported in the tabloids, but at a range of strategies, including alternatives to exclusion such as support units both in and out of school.
St Mungo's High School in Camelon, Falkirk, set up its own pupil support unit last March. "The unit is a haven for pupils who find the larger school difficult," says Andy Mimnagh, the headteacher. "It's not a sin bin. We don't have a sin bin and we don't want a sin bin."
The unit is a large portable building for up to 25 pupils (21 are on roll). There is a teaching area, a small computer suite, a quiet social area, audio-visual equipment, toilets and a kitchen. It operates lunchtime clubs, support groups and music therapy.
"Pupils want to come to the unit," says Mr Mimnagh. "The timetable is suited to each individual, regardless of when the bell rings. Even pupils who have not been referred want to come to lunchtime clubs here and staff are keen to be involved."
One S4 school refuser comes to the unit regularly. "He's been a refuser most of his school career," says Mr Mimnagh. "His parents think this is wonderful - though we haven't got him through the classroom door yet. He's just frightened of school. It's not a behavioural problem. He's an interesting type, a type often overlooked by proponents of sin bins.
"You have to remember there are children who need life skills for themselves and not eight Standard grades. It's a matter of finding the right alternative provision. That takes team work."
An Achievement for All group comprising the relevant teachers and social workers assesses the referrals. Pupils may be referred for prolonged absence, truancy or school refusal. It may be that normal discipline procedures have proved ineffective. Or a pupil may need gradual inclusion after transferring from another school.
"Every pupil has a planned strategy of intervention," says Mary Berrill, the unit's pupil support teacher. "We can draw up a particular curriculum for each subject, where I'll go into mainstream classes to team-teach as well as work individually with them in the unit.
"It's about getting pupils back into mainstream and keeping them there, so it's about supporting teachers as well as pupils.
"In the base the pace is slower and the atmosphere, with music, is more soothing. I never shut and I've never been sworn at. The pupils have a sense of belonging. It's their base," she emphasises. "It's a place of safety and refuge with a family atmosphere.
"I see parents every day. And these are parents often previously disillusioned with school. You have to support the parents too, visiting them at home and such like. You help the parents in order to help the child."
Gayle Penman, a social worker, covers home-school liaison. "I've been working with an S1 pupil with difficulties at school, at home and who was at risk of offending in the community as well as of being excluded. He's been in the unit for two months for 14 periods a week and there has been a dramatic improvement in his behaviour and attitude.
"He's no longer at risk of exclusion, is beginning to like school, and his mother is very positive about the unit and is coping better as much of the stress has been removed."
The support of psychological services and of social work is crucial to the unit, as is the pupil mentoring scheme which began last term: 29 S6 mentors run a lunchtime drop-in centre in the unit where pupils can come for a confidential chat. They also conduct paired reading with S1 pupils and help run workshops for Wisecrack, a drug charity.
Jim McWilliams, an English teacher and mentoring co-ordinator, says: "There are tangible successes in identifying pupils who need befriending and for whom lunchtimes used to stretch out like a jail sentence. It also develops the mentors' skills and confidence."
A motor skills group involves six pupils from S1 to S3 and is run by Lindsey Combe, a PE teacher. She says: "We work on fine and gross motor skills to tackle dyspraxia - 'clumsy child syndrome' - to build confidence and self-esteem, to allow pupils to achieve in PE and to help them pick up a pen to write or draw.
"We do 20 to 25 minutes a week and you can see the improvement because it's a ratio of 1:6. You have to remember that dyspraxia doesn't come on its own. Physical problems will bring behavioural and emotional problems."
Mr Mimnagh argues that the pupil support has to come from many sources. "If we didn't have mentoring, the motor skills group, music therapy and solution focus groups on anti-bullying, raising self-esteem and anger management, then the unit could be seen as a 'sin bin' rather than as part of a positive strategy."
Mary Berrill, the pupil support teacher, while arguing for more staff, says a similar unit could be set up in any secondary school.
"Every state school has the same range of problems that we have. It's about early intervention and reintegration into mainstream. But what you do need is the full support from senior management, which we get.
"It's also about respect. The pupils must develop self-respect and respect others, and that, of course, includes the teachers."