Poll inclusion
Country trackers aim to include publicly reported, nationwide voting-intention polls for the relevant national legislature. Party or first-preference figures are charted separately.
- Included: published fieldwork dates, pollster, sample size when available, source link, and separate party results.
- Excluded: two-party-preferred results, seat projections, approval ratings, election results presented as polls, regional polls on national charts, and hypothetical scenarios that cannot be compared with the main series.
- Missing values: left blank. They are never treated as zero.
Dates, ranges, and elections
Polls are positioned by the end of fieldwork, because that is the latest date represented by the sample. Tables retain the full fieldwork range. Election markers use the exact election date rather than the middle of an election year.
The 1Y, 5Y, 20Y, and All controls change the visible period without changing the underlying archive. When a source has no polling for a period, the chart leaves that period empty.
Headline and trend averages
The summary headline uses polls ending within 45 days of the latest available fieldwork. Each poll is weighted by recency, using a 30-day half-life, and by the square root of its sample size. The square root prevents one unusually large sample from overwhelming every other poll.
Rolling average
A local moving window that follows nearby observations. It is the default because it is relatively easy to read against the points.
Smooth average
A wider moving window for a calmer long-term line. It reduces visual noise but can respond more slowly to genuine changes.
Exponential average
An exponentially weighted series that gives progressively more influence to recent polls.
Gaps and discontinuities
Trend lines break across long polling gaps instead of drawing a straight line through years with no evidence. Loaders also exclude table types and implausible rows that do not belong in the comparable national party series.
A sudden change can still reflect a real political event, a pollster change, or a source-table boundary. The points, pollster filters, source table, and range controls remain available so visitors can inspect it.
The global map
Each published country defines a local left and right grouping for the limited purpose of showing which broad bloc is ahead. Red indicates a left-bloc lead, blue a right-bloc lead, and purple a close race.
These classifications are not relative rankings. A blue country is not necessarily further right than another blue country, and parties in different countries are not assumed to be equivalent. The country summary documents the parties included in its local grouping.
Live, cached, and fallback data
Country loaders request compiled public polling tables from MediaWiki and retain the original source links where available. Results may be cached in the browser for seven days. A checked local archive or current-cycle snapshot keeps the page usable when a source or network request fails.
The chart status states whether it is showing a live archive, cached data, or bundled fallback data. A fallback is not presented as a fresh internet update.