The election-day exit poll methods developed by Warwick Statistics professor David Firth surprised the world yet again at 10pm on election day, immediately after the polling stations closed.

The exit poll, commissioned jointly by broadcasters BBC, ITV and Sky, correctly predicted that the Conservatives would be the largest party in a hung parliament as the result of last Thursday's election. This was quite different from what had been expected by most politicians, commentators and the global financial markets — and a long way short of the increased majority that PM Theresa May had wanted when she called a snap election (three years earlier than scheduled).

Professor Firth said:

It's very pleasing that this continues to work so well — and especially pleasing that most people seem now to trust that the exit-poll prediction will usually be fairly accurate, regardless of the various pre-election opinion polls and punditry that might suggest otherwise.

For the full story and details of the methods used, see warwick.ac.uk/exitpolling.

The exit-poll design and analysis methods developed by David Firth (with political scientist John Curtice from the University of Strathclyde) were used again at this week's General Election by all of the major UK broadcasters.

At 10pm on election day the on-air seats prediction (simultaneously on BBC, ITV and Sky) based on the exit poll was: Con 316, Lab 239, SNP 58, LD 10, others 27. The actual result of the election was Con 331, Lab 232, SNP 56, LD 8, others 23.

The 2015 exit-poll prediction was thus not "spot on" as it had been in 2005 and 2010. Many commentators had warned beforehand that the 2015 election would be an especially difficult one to predict. The exit-poll prediction was startlingly different from what had been indicated by commercial pre-election voting-intention polls. (e.g., see The Observer on 10 May, After the exit poll, a tsunami raged across the political map) The exit poll strongly indicated the Conservatives as largest party, and the ultimate outcome of a small Conservative majority was clearly not ruled out. This was in stark contrast to predictions from pre-election polls, which had consistently shown Conservative and Labour neck-and-neck with neither party close to an overall majority.

There were some notable public quotes, most prominent of which came from the former Liberal Democrat leader Lord Ashdown, who was interviewed soon after 10pm on the BBC:

If this exit poll is right, I will publicly eat my hat on your programme.

(He was referring to the predicted collapse of the Liberal Democrats to just 10 parliamentary seats. In the event, it turned out even worse than that for the Liberal Democrats, who won just 8 seats. Lord Ashdown failed to keep his hat-eating promise, though!)

For more information on the methods and their performance at previous UK general elections, see Exit Polling Explained.

Dr Heather Turner, statistical consultant and currently an Associate Fellow of Warwick Statistics, has been invited to give an intensive one-day course Introduction to Generalized Nonlinear Models in Zurich on 11 May 2015. The course is based on Heather's work as a Senior Research Fellow at Warwick, which included the development of award-winning software package gnm.

Heather's work and her views on statistics, science and R development are featured in this extended interview recorded at the useR! 2014 conference in Los Angeles.

The Department of Statistics is pleased to be a partner in the newly announced ESRC Doctoral Training Centre at Warwick.  This new funding from ESRC will provide exciting PhD opportunities for students whose interests are in statistical methodology for social-science applications.  The first studentships under this scheme will be available from October 2011, and more details will be announced shortly.  (Departmental contact: David Firth)

A direct upshot of the 2008 CRiSM workshop on composite likelihood methods is a special issue of the major international journal Statistica Sinica, with 14 new peer-reviewed papers on this topic.  The special issue was edited by N Reid (U Toronto), B Lindsay (Penn State U) and K-Y Liang (Johns Hopkins U), and can be found online at

http://www3.stat.sinica.edu.tw/statistica/j21n1/21-1.html