Bill Harvey: Look around you

A wise man once said ‘as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don’t know we don’t know.’

A major advance in clarifying our knowledge base has been made in the development of the Cochrane Library online (www.cochranelibrary.com) which I heartily recommend to readers. The site regularly publishes reviews of all the current published evidence and comments on its strength in proving a particular concept. It has also developed a bias risk tool which helps to decide upon the objectivity of published claims in the literature.