PHILOSOPHERS investigating the nature of knowledge and the best methods of acquiring it have always distinguished between knowledge of facts and knowledge of techniques.

Knowing that Everest is the highest mountain, and knowing how to measure the height of mountains, are respective examples of the two kinds of knowing. The interesting question is, which is more important?

Obviously enough, an education system worthy of the name should equip people with both kinds. But it is still worthwhile to ask which is more important, for the equally obvious reason that no head can first cram in, and then later recall at need, everything that passes as currently accepted fact. What's more, the number of currently accepted facts is tiny in comparison with what we know we still do not know, which is in turn probably a tiny fraction of what might be knowable.

So although everyone coming out of an educational system should at least know the periodic table, the salient dates of world history, the fundamentals of geography, and other kinds of basic information, they are much more in need of knowing how to find things out, how to evaluate the information they discover, and how to apply it fruitfully.

These are skills; they consist in knowledge of how to become knowledgeable.

Acquiring information is now easier than it has ever been because of the internet. But information is not knowledge. The trouble is that quantity of data, especially data available online, is no guarantee of quality. For online data in particular there is no expert filter that weeds out poor information and misinformation. The only protection against either is for internet users themselves to exercise caution.

In one way it is no bad thing that the internet is such a democratic domain, where opinions and claims can enjoy an unfettered airing in most parts of the world. Expert filtering could easily provide a cloak for censorship. This increases the necessity for internet users to be good at discriminating between high and low-quality information, and between reliable and unreliable sources.

We teach research skills in higher education differently for the sciences and humanities, and there is much to be taught in both. In the sciences, laboratory technique and experimental design and methodology are fundamental; in the humanities, the use of libraries and archives and the interpretation of texts are in the basic tool kit. This is all part of the machinery of how information is acquired, and at its best it constitutes evaluation as well as discovery. But most of the knowledge or purported knowledge we think we have is actually acquired second-hand from indirect sources, and it is this process that requires special care.

Knowing how to evaluate information, therefore, is arguably the most important kind of knowledge that education has to teach. Some schools offer courses in it, and there are a number of books about it on the market. But only the International Baccalaureate makes critical thinking ("theory of knowledge") a standard requirement, and in this as in so many ways it leads the field, because critical thinking and evaluation of claims to knowledge should always be right at the centre of the educational enterprise.

I wonder whether the need for critical thinking lessons is more urgent in the humanities than the sciences because the latter, by their nature, already have it built in. The science lab at school with its whiffs, sparks and bangs is a theatre of evaluation; the idea of testing and proving is the natural order there, and the habits of mind thus acquired can be generalised to all enquiry.

When we talk of scientific literacy, one thing we should mean is acquisition of just this mindset; without it, too much rubbish gets through.

From issue 2668 of New Scientist magazine, 06 August 2008, page 48

New Scientist 06 August 2008