But where should parents look for ideas about discipline? In the absence of anything better, many parents, who were smacked themselves, smack their own children - which they still have a right to do in this country. A Department of Health study in 1995 found that 91 per cent of children had been hit, and almost one in six had experienced "severe punishment" by a parent. Research evidence also shows that it is not the case that underprivileged parents smack more than other parents; the stress of a high-powered job can make parents hit out at their children.
But the old maxim of "spare the rod, spoil the child" no longer holds sway in modern ideas of discipline. Physical punishment has already been outlawed in Austria, Cyprus, Finland, Norway and Sweden.
Barnardo's is part of an alliance of organisations called "children are unbeatable", which is campaigning for physical punishment of children to be made illegal in the UK.
"Physical punishments like smacks make children too angry to be sorry for what they've done," writes Penelope Leach, in a Barnardo's booklet entitled Getting Positive About Discipline. "In addition, they can easily escalate from a quick slap to something more severe and possibly dangerous."
"Positive discipline" is the name of the game these days. As Leach explains: "Positive discipline focuses on good behaviour; expects it; makes sure children understand what it is and why; rewards children for it and hopes that will motivate them to keep on."
What really matters, according to Leach, is "a positive balance overall, rather like a bank account. Within limits, a bad day can put you in the red, but a good one can put things right again."
Alternatives to smacking might include a "time out" approach - where a child is set apart until they calm down - or the withdrawal of special privileges, so that children learn that their bad behaviour has consequences for them.
As Tim Kahn, author of Bringing Up Boys (Piccadilly Press), says, "If you create a good talking and listening relationship with your child, you are more likely to be able to manage the difficult points successfully."
Two booklets, entitled Getting Positive About Discipline and Why Speak Out About Smacking are available from Barnardo's, priced pounds 1. Tel 0181- 550 8822 for details.
Helen Pattinson is the mother of two boys, Jamie, six, and Ryan, four. They live in Newcastle.
"The boys are very boisterous, jumping around all the time, and they fight a lot. Ryan went through a stage of ripping my wallpaper off. They'll throw all their toys around, just for the sake of it, or pour all your shampoo down the sink. Sometimes nothing seems to work: they just keep doing it.
"I find it very difficult. I know smacking doesn't work, but if I'm honest, I still smack them sometimes, more for release when I'm very tense.
"The Barnardo's Caring Start course I went on looked at finding alternative ways of handling things, like getting onto their level and explaining the consequences of what they were doing, rather than screaming at them.
"I can see the logic behind it, but when it comes to it, it's hard to put it into practice because you're getting rid of your own frustration.
"But I don't smack them as much now. I try to find realistic punishments; things I'm going to stick to. If I ground them and don't let them play outside, that tends to work a bit better. They really hate being kept in.
"The Caring Start course suggested giving the children more choices. It used to be a nightmare going on the bus with Ryan, so I gave them a choice of train or bus. They chose the train, and then they were fine.
"If you interact with them more than talking at them, you get more response; you'd rather yourself that people talked to you than ordered you. The course also suggested giving them more praise. If I say to Jamie when he's doing something good, he'll go out of his way to please me. Often when children are being naughty, it's just to get your attention."