UK Election Data Vault

Pollster Ratings

Our pollster ratings are meant as a guide to recent performance of pollsters in UK general election polls. They are based on three components: accuracy, longevity and membership of the British Polling Council.

Seventy percent of a pollster’s score comes from their accuracy in predicting the most recent three UK general elections. The measure used depends on the differences between the national share of the vote (for the three largest parties) and the final poll fielded before polling day. A perfect prediction of each of the last three elections would contribute seventy points to a pollster’s score.

Ten percent of a pollster’s score comes from their longevity in polling UK general elections. A pollster is awarded ten points if the published a poll conducted during each of the last three parliaments (i.e. between 2010-15, 2015-17, 2017-19) New pollsters have a longevity score of zero.

Twenty percent of a pollster’s score comes from membership of the British Polling Council. Members receive twenty points and non members zero.

Pollster ratings are used in the calculation of our polling average. They have been back calculated so contemporary ratings are used to weight the poling average. For example, the pollster rating used to weight polls for the 2010 general election are based on accuracy in predicting the 1997, 2001 and 2005 general elections.