Norman Fenton is Professor in Risk Information Management at Queen Mary University of London and also a Director of Agena, a company that specialises in risk management for critical systems.
One of the major messages currently being pushed everywhere by the UK Government about COVID-19 is the claim that “1 in 3 people who have the virus have no symptoms”. In fact, if we trust the Government’s own data, this claim is massively exaggerated. The true figure – as we explain below – is more like 1 in 38*. Moreover, using data from
an ongoing study at Cambridge University (in which only people without symptoms are tested) we conclude that 96% of such people who test positive do not have the virus (i.e. they are mostly false positives).