All you need to know about the science of opinion polling

by Stephen Tall on October 26, 2006

  • According to Mori in the Financial Times (22nd Oct), the Tories trail Labour by 2% – 35% to 37%.
  • According to Communicate Research in The Independent (24th Oct), the Tories lead Labour by 6% – 38% to 32% – with the Lib Dems plummeting to 14%.
  • According to ICM in thegrauniad (25th Oct), the Tories lead Labour by 10% – 39% to 29% – with the Lib Dems increasing to 22%.

From this we can conclude, within the +/-3% margins of error, that:

  • The Tories are either more popular than Labour or less popular than Labour, scoring somewhere between 32% and 42%.
  • Labour are either more popular than the Tories or less popular than the Tories, scoring somewhere between 26% and 40%.
  • The Lib Dems are either losing support or gaining support, scoring somewhere between 11% and 25%.

So that’s all clear then.

Question: why do reputable news media outlets and The Independent devote so much space to discussing individual polls which, when viewed in isolation, are about as reliable as a Tony Blair answer at Prime Minister’s Questions?