Monday, 28 February 2011

That Yougov poll and the missing question

You'll have seen the recent Yougov poll and you might even have thought about how the weighting affected it.  Like me, you may have been wondering how the raw data converted to the weighted data, how this population of party identifiers:
Labour 291
Conservative 222
Liberal Democrat 67
Scottish National Party 289
Others 67
None / Don't know 322

was adjusted to become this population in the weighted data:
Labour 478

Conservative 163
Liberal Democrat 126
Scottish National Party 201
Others 25
None / Don't know 266

Very crudely, that means that each person who identifies as SNP who was polled counted as 0.7 of a person and every person who identifies with Labour was counted as 1.6 (Con - 0.7, LD - 1.9).  Just as interesting is the newspaper weighting, though, this:
Express / Mail 196
Sun / Star 100
Mirror / Record 94
Guardian / Independent / Herald 219
FT / Times / Telegraph / Scotsman 188
Other Paper 146
No Paper 315
became this:
Express / Mail 151

Sun / Star 201
Mirror / Record 251
Guardian / Independent / Herald 76
FT / Times / Telegraph / Scotsman 75
Other Paper 252
No Paper 252

A Daily Record reader counts as two and three quarter people in this poll and a Sun reader as double while a Herald reader is trimmed to just one third of a person and a Scotsman reader to two-fifths of a person.  It becomes, perhaps, even more interesting when you read this piece by Mike Smithson where he points out that Yougov is using old circulation figures for its newspaper weighting (the Record's readership is now under 307,000) and the dangers inherent in that were already laid out by Nick Sparrow.

It's fascinating, of course, to speculate on how wrong the poll is, but that's not what most intrigues me.  What most intrigues me is that this poll was commissioned by the Greens and it had another question in it which hasn't been published.  The other question was how the people polled felt about the Greens' idea of increasing tax in Scotland to offset the effects of the Westminster cuts.  It's up to the client what questions are published and when - I can't help but wonder what on earth could have been in the answer to that question that persuaded the Greens that it should be kept secret.

Answers on a postcard to ...

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