A quarter of the meetings were with someone older and 5 per cent of youngsters did not tell anyone where they were going. But 74 per cent told a friend and almost half told a parent.

Fourteen per cent of nine to 11-year-olds had chatted online with a stranger and 2 per cent of those went on to meet them.

That rose to four in 10 of 16 and 17-year-olds, with 14 per cent of those meeting.

The report UK Children Go Online, based on responses from 1,511 children and 906 parents, by Sonia Livingstone and Magdalena Bober of the London School of Economics, says: “Arguably the (internet) safety campaigns have been successful. While one third of those who go online at least once a week have made friends online, only a few go on to arrange a face to face meeting and nearly all those tell someone they are going, take a friend with them, meet someone of their own age and have a good time.

“However, it might be a cause for concern that few children tell an adult about a meeting or take an adult with them who would be better qualified to intervene in a potentially dangerous situation.”

Only 16 per cent of parents thought their children had seen porn online, whereas 57 per cent of nine to 19-year-olds had done so.

A third of those surveyed had been bullied online and 28 per cent had been emailed unsolicited sexual material.

Only one in three said that pornography filtering software had been installed on their computer. About half (49 per cent) worry about being contacted by dangerous people.

Nine in 10 used the internet for homework and and a fifth of secondary pupils had copied something from the web for a school project and passed it off as their own.

But television has not lost its grip on young people’s affections. Asked what they would miss most if it disappeared tomorrow, 31 per cent opted for TV, 28 per cent their mobile phone, 14 per cent the games console, with the internet and computers coming in at 10 and 9 per cent respectively.

Books would be missed most by only 7 per cent of children.