Polling and electoral results are weighted according to the age of the poll, the amount of people polled, and the reliability of the polling firm.
The 2004, 2006, and 2008 federal elections are included because past voting behaviour tends to be a major predictor of future behaviour. Obviously, recent elections are weighted more heavily than older elections.
Older polls are dropped as newer ones are added.
Polling firms are weighted according to their accuracies in national and provincial elections since 2008. In the name of openness, here are the reliability factors of the various polling firms (updated as of the 2010 New Brunswick election) :
Angus-Reid Strategies - 1.11
Corporate Research Associates - 0.98
Léger Marketing - 0.84
Ipsos-Reid - 0.84
EKOS Research Associates - 0.79
Mustel Group - 0.72
Nanos Research - 0.70
Environics - 0.68
Harris-Decima - 0.67
Strategic Counsel - 0.52
Segma Unimarketing - 0.47
CROP - 0.12
Abacus Data - 0.08