Uniform national swing
Encyclopedia
Uniform national swing, or UNS is a system for translating opinion poll
s, which give overall vote proportions, to expected eventual parliamentary seats in a constituency based first past the post system, as in the UK general elections. Under the uniform national swing, changes in the vote proportions (swing
) since the previous election are assumed to be constant across all constituencies. By applying this change to the previous per-consistuency based vote proportions, a prediction for which party would have the most votes in each constituency may be made, which is then counted and totalled for a final seat count.
Alternative methods exist, such as the proportional national swing system. However, UNS has proven acceptably accurate in the past, and so is commonly used in UK media for seat count predictions.
Opinion poll
An opinion poll, sometimes simply referred to as a poll is a survey of public opinion from a particular sample. Opinion polls are usually designed to represent the opinions of a population by conducting a series of questions and then extrapolating generalities in ratio or within confidence...
s, which give overall vote proportions, to expected eventual parliamentary seats in a constituency based first past the post system, as in the UK general elections. Under the uniform national swing, changes in the vote proportions (swing
Swing (politics)
An electoral swing analysis shows the extent of change in voter support from one election to another. It is an indicator of voter support for individual candidates or political parties, or voter preference between two or more candidates or parties...
) since the previous election are assumed to be constant across all constituencies. By applying this change to the previous per-consistuency based vote proportions, a prediction for which party would have the most votes in each constituency may be made, which is then counted and totalled for a final seat count.
Alternative methods exist, such as the proportional national swing system. However, UNS has proven acceptably accurate in the past, and so is commonly used in UK media for seat count predictions.
External links
- BBC seat calculator using UNS, for the United Kingdom general election, 2010