How do you judge the risks and benefits of new medical treatments, or of lifestyle choices? With a finite health care budget, how do you decide which treatments should be made freely available on the NHS? Historically, decisions like these have been made on the basis of doctors' individual experiences with how these treatments perform, but over recent decades the approach to answering these questions has become increasingly rational.

Helen Joyce is a former editor of Plus magazine who now works as a journalist for The Economist. In August she's off to Brazil to be the paper's Brazil Bureau Chief. In between packing and learning Portuguese she has found time to tell Plus all about her varied career and the role maths has played in it.

"It's a match!" cries the CSI. At first glance it might seem that if the police have matched a suspect's DNA to evidence from the crime scene, then the case is closed. But some statistical thinking is required to understand exactly what a match is, and importantly, how juries should assess this as part of the evidence in a trial.

Tonight, in the final televised debate ahead of the election, the three main party leaders will talk about the economy, the recession, public sector debt, spending or cuts, and more. All will use statistics to back up their points or to pull apart their opponents' arguments. But how can we work out whether to believe the figures and what do they really mean?


Being killed in a peacekeeping mission apparently depends on your nationality, at least if you're a soldier in the Spanish army. On the 1st of February 2010 the Colombian soldier John Felipe Romero serving in the Spanish army was killed in a terrorist attack in Afghanistan. It was then made public that so far 43% of the Spanish troops killed in attacks by local forces in Afghanistan and Lebanon have been foreigners. This is in striking contrast to the fact that foreign nationals make up only 7% of the Spanish army as a whole.

Lack of statistical detail leads to wrong conclusions

Genomics is one of the fastest moving areas of science and Gavin Harper, a mathematician and statistician, has put himself right at its centre. He works for Oxford Nanopore Technologies, a company which is developing new technology for analysing molecules and sequencing DNA. With 75 employees from 18 different countries and all sorts of scientific backgrounds, Gavin's work environment is nothing like the solitary paper-and-pencil affair traditionally associated with mathematics.

Stats, damn stats and genetics

We have all become more aware of the dangers of influenza this year, but why is it so dangerous? Julia Gog explains that the unusual structure of the influenza genome can lead to dangerous evolutionary jumps, and how mathematics is helping to understand how the virus replicates.