Bullying is a fact of school life, but headteachers now have a legal obligation to take steps to prevent it.

Research published last year suggested that as many as four in children had suffered from bullying at some time.

There was a marked split between primary schools - where 27% claimed to have been bullied in the previous six months - and secondary schools, where only 8% had.

It would be wrong to understate the genuine misery bullying can cause, but any parent knows that at the age of six or seven, one week's bully is the next week's best-friend-for-life, so those figures need to be taken with a pinch of salt.

But if it is persistent, and when combined with the emotional volatility of adolescence in secondary schools, the problem can be more acute and psychologically damaging.

Policy and practice

The 1998 School Standards Act says that a headteacher "shall determine measures ... to be taken with a view to" among other things, "encouraging good behaviour and respect for others on the part of pupils and, in particular, preventing all forms of bullying among pupils".

The guidance on bullying from the Department for Education in England, dating back to 1994, is being reviewed in view of the new law. It expects to issue a new version, with a video, in a matter of weeks.

"It tends to be dealt with at local level, " said a spokeswoman. "We are not here to tell schools what to do."

All school staff are told to be alert to signs of bullying, as pupils may see failure to respond to incidents or allegations as tolerating bullying, which the department says is usually part of a pattern of behaviour rather than an isolated incident.

Speaking out

The message to pupils is not to suffer in silence but to report any bullying they experience or witness to staff or to an older pupil they can trust. In some schools effective use has been made of trained pupil counsellors who can offer advice to bullied pupils in confidence.

Professor Pamela Munn, the director of the new Anti-Bullying Network in Scottish schools, reinforces this.

"In the past, secrecy and silence have nurtured bullying," she said.

"Bullies and victims have colluded to keep the problem hidden, and adults have been able to say that they would take action if only pupils would speak up."

Where progress had been made, it was often been down to pupils taking responsibility for their own actions and becoming involved in helping their peers.

Pupil power

"Pupils are demonstrating that, if adults are willing to give them responsibility backed by support and training, they can develop mediation and counselling skills and help to create a more positive system of school discipline," she said.

Experts say it is a matter of changing the atmosphere or culture in a school to stop bullying occurring or to nip it in the bud.

One problem for the school's management is gathering evidence.

In the case of the Nottingham schoolgirl withdrawn from school by her parents after complaining of persistent bullying by eight other girls, the headteacher, Tim Moralee, said youngsters could feel intimidated.

"One strategy that's worked very successfully is to place envelopes into which youngsters can place anonymous information in their tutor groups," he said.

Gathering evidence

"This is helpful in the sense that people can feel free and protected in giving information when, in a bullying situation, to provide information about bullies is potentially quite dangerous for youngsters and quite a threatening situation to put them in.

"Our evidence base has grown as a result of this strategy."

This raises the obvious danger of unfounded allegations being made, of course - indeed, it could even be used as a bullying tactic.

Excluding bullies from school is supposed to be a last resort.

The Department for Education (DfEE) guidelines on the subject say: "A decision to exclude a child should be taken only in response to serious breaches of a school's discipline policy, and if allowing the pupil to remain in school would seriously harm the education or welfare of the pupil or others in the school."

The law allows head teachers to exclude a pupil for up to 45 days in a school year. But the DfEE says individual exclusions should be for the shortest time necessary, "bearing in mind that exclusions of more than a day or two make it more difficult for the pupil to re-integrate into the school."

And it says expelling a child "is a final step in the process for dealing with disciplinary offences when a wide range of other strategies have been tried and have failed."

Section 28

One of the complications for schools is the now notorious Section 28 of the Local Government Act, which the government is - controversially - trying to repeal.

This is the clause which bans local authorities from promoting homosexuality.

This is commonly misreported as banning schools from promoting homosexuality. It actually says nothing about schools, and school sex education policies remain a matter for the governors to decide.

But research has suggested that unease among teachers about the implications of the clause have meant they have been reluctant to tackle cases of homophobic bullying.

This is one of the most common forms of verbal abuse, with boys especially who are quiet or work hard being derided as a "poof" or "queer".

The National Association of Head Teachers, which has issued its own guidelines on bullying, has warned schools that if they are not careful they could face legal action on the issue.