Polling: Voting Intention

Every pollster is assigned a score derived from their historic accuracy. This is displayed as a 0–100 scale in the coloured circles beside each pollster. Purple circles (47) indicate a new pollster without a track record, assigned a provisional penalty score to prevent unproven methodologies skewing the average.

To prevent high-volume pollsters from skewing the average through sheer quantity, weights are adjusted for frequency. If a firm publishes multiple times within a 10-day window, their total weight is distributed across those polls.

The trendline uses a Time-Based Kernel Average (a 35-day window).

A robust two-pass system measures how far a poll deviates from the initial trend. Extreme outliers have their influence drastically reduced or zeroed out.