Poll Average Details- London Mayor - 2008-05-01 16:00:00

The Poll Average is a weighted and adjusted number.
[Mid Date Column] All times are calculated by the middle date of the poll if it spans multiple days.
A time window of 2 months prior to the most recent poll is used.
[Time Weight Column] Polls are weighted in the amount they contribute to the final results in a linear fashion in this time window - the newest poll has a weight of 1, a poll 30 days prior will have a weight of 0.5 and a poll 60 days out will have a weight of 0. If the same pollster has more than one poll in this time period, only the newest will be used.
[Internal Column] If a poll is marked as being an internal poll for one of the candidates, it's weight will be halved.
[Candidate Columns, Bias] OurCampaigns has calculated partisan bias figures for all Polling Firms based on data from final vote totals in races they have polled. These amounts are subtracted from the poll result - in the case the bias figure is negative it will effectively be added to the poll result and appear as two dashes (minus a negative = plus). [TOTAL Row] The adjusted weights are summed for each poll result and the adjusted poll results for each candidate are multiplied by the poll weight and then summed. Each candidate's poll sum is divided by their weight sum to give the total.

Poll	Mid Date	Time Weight	Internal	Boris Johnson Spoiled Ballots	Ken Livingstone	Brian Paddick	Siân Berry	Richard Barnbrook	Gerard Batten	Matt O'Connor	Blank - Void	Lindsey German	Winston McKenzie	Alan Craig
MORI	4/23	X 1.00000		38.0000 - -6.0769 bias	41.0000 - 1.3636 bias	12.0000 - 0.8628 bias	3.0000 - 1.8598 bias	2.0000 - 1.0802 bias	1.0000 - 0.0902 bias	0.0000 - 0.0000 bias		0.0000 - 0.0000 bias	0.0000 - 0.0000 bias	1.0000 - 1.0204 bias
YouGov	4/18	X 0.91667		44.0000 - -2.2623 bias	37.0000 - -3.7254 bias	12.0000 - 2.5136 bias	3.0000 - 1.6851 bias	1.0000 - 0.1919 bias	1.0000 - 0.5460 bias	1.0000 - 0.0925 bias		0.0000 - 0.0000 bias		0.0000 - 0.0000 bias
Mruk Cello	4/14	X 0.85000		44.0000 - -5.4169 bias	45.0000 - 3.1926 bias	9.0000 - 2.1193 bias
ICM Research	4/1	X 0.63333		42.0000 - -0.2225 bias	41.0000 - 2.2922 bias	10.0000 - 3.5534 bias	4.0000 - 1.8427 bias	1.0000 - -2.0343 bias
TOTAL				45.655674	40.299778	8.754267	1.455614	1.404816	0.691809	0.434022	0.000000	0.000000	0.000000	-0.010643