Net Results: How do you know when a source of information on the internet is a trusted one? It isn't an easy question to answer, but if you are a newspaper reader then you probably already have various screening systems, hype metres and rubbish detectors that switch on as you move through an article.

In the broader realm of newsprint, you almost surely have a sense of the papers you trust and don't trust (in general terms - few of us have entirely rosy views on any publication, I think). Within those papers, you also have the writers whose work you find more reliable than others. The same is true for radio and televisios programmes, and so on.

But the internet is a different kettle of fish. I'm mulling this notion over because I was speaking to an academic last week about how, if some adults find it hard to filter sources of information on the internet, children seem to find it almost impossible. And not young ones, either. Secondary students as well as college students will quote the most spurious online sources in research papers, say friends of mine who are teaching these groups. "They assume that if it is on the internet, it must be reliable," said the academic. But why?

It's a puzzler. It's not as if children or college students can't pick out porkies or even subtly embroidered truths - we all know how dismissive even a young child can be of something that doesn't ring true. And a waffling grown-up? They can spot one at 50 paces.

But fire up the old browser and anything stumbled upon, the most unlikely websites, take on the weight of authority. From whence does authority derive in the online world?

Everywhere, and nowhere, is the answer. With the internet, you have a vast medium that, thanks to Google, can be searched in seconds. Want to know about asparagus? In one second, Google can send you to 1,820,000 websites that refer to the vegetable.

By contrast, you'd be hard put to search out 100 articles, radio broadcasts or television shows that mention asparagus, and it would be a good few hours' work at least. That's part of the problem. Research used to be - if not hard - then at least time- consuming and limited to sources that were considered authoritative enough to be catalogued. Authoritative generally meant a named author from a known publication.

All this information was then cited in a bibliography (woe betide the student who forgot to underline the title of the book or overlooked the volume number of the magazine in a citation). Does anyone remember foraging through the green volumes of the Periodic Guide to Literature in search of an article on farming in China or Napoleon or mollusks? If the journal was in the guide, you knew it had some sort of authority.

The internet, though, is not designed with such restrictions on worthiness. That, of course, is its greatest strength - information can be set free and even national governments cannot stand in the way of the internet's vast network. Cut it off here, and it sneaks through there. The problem is that many people come to the internet treating it as a media source with some in-built filtering system. Adults do it all the time, as you realise if you spend any time at all on e-mail lists or discussion boards. Some URL is offered as evidence in an argument. You go look at it and might notice the information is very outdated. You might also know it is incorrect. But there it is, offered up as authoritative and true.

Children seem particularly vulnerable to assuming that the very fact that something is online lends it authority. This isn't surprising when they seem to get little or no teaching in reading media, all forms of media, critically. Such instruction is deemed appropriate for university degree courses in media studies, but not seen as a basic tool for learning, something that needs to be taught alongside reading skills at primary level.

I don't think it is any surprise that today's university students often draw uncritically upon the net as a font of authoritative information - after all, they are the generation that first got online as young kids, and if media literacy is lacking in the curriculum today, it wasn't even thought about a decade ago, particularly not in the context of that newfangled net. Time for some redress, then. Children need to learn those filtering skills in a more formalised way, and they need to approach the medium they rely on most - the internet - with a sharply critical eye. http://weblog.techno-culture.com