Dad, Dad, can you help us with the Internet?” That is the regular cry from our back bedroom as the children struggle yet again to get something useful from the Web.

I drag myself up the stairs to help them make sense of a system I hardly understand myself. “Where can I find something on magnetism?” “Why can’t it tell me when the Queen was crowned?” “I’ve got 20,000 sites from the search. Which ones should I look at?” The questions are incessant, the frustration intense, but the prize is great. When they succeed in finding a photo or a piece of information for some homework, their pride is enormous.

But given the time and trouble of using the Internet, how worthwhile is it as an educational tool? My nine-year-old daughter Eleanor was recently asked to write a short biography of an author. She chose Judy Blume and used a basic search engine to find relevant sites. Within a minute of logging on she had found fan sites, publishers’ sites and biographical entries. So far so good, but once she started extracting details she became rapidly confused.

Three websites had varying information on Blume’s marriage: one said she married John Blume, another said she was divorced, another said she was married to George Cooper. Eleanor wanted to know which was true. I had to do a bit of Internet detective work myself and found yet another site. It said that Judy Blume was now on her third marriage, to George Cooper.

One of the sites Eleanor had found contained an extract from an old biography. Another site was from a homework project done by a 12-year-old American girl who obviously hadn’t checked her own facts. That child’s site (how many UK schools encourage children to put their homework on the Internet?) points up a key problem - reliability of information. As editor of a BBC programme, I expect journalists to assess whether information is true. But children think that what they see on a computer must be right.

To my daughter that Blume site, made by a child, looked as believable as an official reference. Once I’d explained the confusion, she still had a superb range of reviews, photos and data to produce a well-informed little biography of her own. And the confusion pointed up a useful lesson - don’t rely on everything the Internet says.

Learning to assess sources of information is an education in itself, but inaccuracy shouldn’t be a selling point for any system. Maybe it should be possible to restrict children to Internet sites that pass some standard of factual reliability?

For my son Matthew, who is 11, the Internet is a huge source of fun. He knows how to find the information he wants, but, like many adults, he can’t resist the temptation to explore. He might start on a piece of information-finding, but will soon meander off into a chase for irrelevant bits of music or pictures.

When he gets the information, he’s far more interested in making it look pretty on the page than he is in reading or understanding it. Often it’s not until he prints it out that he will really read it. Yet in recent months he’s found information on Tudor architecture, Catalonia and mining techniques in the kind of detail that no encyclopedia could ever provide. It’s just that it takes him hours of fiddling to find it and present it in a way he’s happy with.

So what has the Internet brought our household? Apart from a huge store of information, it’s teaching the children to assess information, to value presentation and not to be too distracted.

Maybe those lessons are being learnt because Dad needs to sit with them for much of the time. But what’s wrong with something that obliges parents to get involved with their children’s learning?

Peter Horrocks is editor of BBC1‘s ‘Panorama’