1. Official source
Published indicator observations come from identified official datasets. Source attribution and indicator identity stay visible on the relevant data surfaces.
Methodology
Official data, explicit years, reproducible comparisons.
World Discovery keeps source identity, observation year, units and geography attached to the values it publishes. When values are not comparable, the interface does not present a numerical difference as if they were.
2. Observation year
The year shown with a value is the observation year for that value. Missing observations are not silently filled from a different year.
3. Comparable context
Differences are calculated only when the compared observations use compatible indicators, entities, units and observation periods.
4. Deterministic calculations
Rankings, differences and revision calculations are produced from stored numerical values by code rather than invented or estimated by a language model.
5. Provenance
Machine-readable and human-readable outputs are built from the same retained source records wherever a corresponding data export is published.
6. Stable publication
Maintained data pages use stable URLs, canonical metadata and explicit source context so users and search systems can identify the current public surface.
How to read World Discovery data
Coverage can differ by indicator, country or territory and year. A lower coverage count means that the verified snapshot contains fewer usable observations for that indicator and period; it does not imply that another year's value was substituted.
Country comparisons keep each observation year visible. If two values come from different years, both values may still be shown for context, but a difference is not presented as a same-period comparison.