Source methodology

Sources are tiered by authority, and higher tiers carry more weight in confidence scoring.

Source tiers

Tier 1 — official government and international statistical bodies (World Bank, Eurostat, OECD, national statistics offices, immigration authorities). Highest trust.
Tier 2 — recognised institutional sources (e.g. major university rankings, official university pages).
Tier 3 — reputable aggregators, used only after legal review and paired with a higher-tier source.

Trust & reputation

Each source carries a trust score and a reputation score derived from its verification success rate, accuracy (outlier rate), and coverage contribution. Sources that repeatedly conflict or fail are down-weighted.

Legal & attribution

Sources pass a legal-review gate before any collection, and attribution is shown on the pages that use them.