Understanding British Exit Polls: Accuracy and Impact

When Can You Start to Know Who’s Won on Election Night?

In Britain, there is an exciting answer just after the polls close at 10 p.m. For the past two decades, three major broadcasters reveal the results of the national exit poll at this time. The exit poll, conducted by a team of statisticians and political scientists, has been remarkably accurate in recent years, providing a picture of the election results before the votes are fully counted.

What Is an Exit Poll?

An exit poll is a survey of voters conducted right after they have voted. In the UK, the exit poll involves asking over 20,000 people at about 130 voting sites across the country to fill in replica ballot papers as they leave the polling place. The British exit poll has been a single comprehensive survey at each general election since 2005, jointly funded by major broadcasters, including the BBC, ITV, and Sky.

Accuracy of British Exit Polls

Over the years, the accuracy of British exit polls has significantly improved. In the past five general elections, the exit poll has accurately predicted the number of parliamentary seats won by the leading party within an average deviation of four seats. In the 2019 election, the exit poll was only three seats off from the winning party’s total, demonstrating its high level of precision.

How Do British Exit Polls Work?

The effectiveness of the British exit poll is attributed to meticulous planning and execution. The survey is conducted by a team of experts who approach voters directly as they exit polling stations. By gathering real-time data on voting preferences, the exit poll provides valuable insights into the likely outcome of the election before official results are announced.