Methodology

Source tiers

• Tier 1 — Primary agency. WHO, CDC, ECDC, PAHO, NICD, national or state ministries of health. A single Tier 1 source is sufficient to publish a pocket as verified.
• Tier 2 — Wire service. Reuters, AP, Bloomberg, AFP, DPA. A single Tier 2 source is sufficient to publish a pocket as confirmed.
• Tier 3 — Major outlet. NYT, BBC, Washington Post, Guardian, NBC, CNN, NPR, FT, WSJ. A pocket reported by a single Tier 3 source publishes with a "seeking 2nd source" badge.
• Tier 4 — Local or single-publisher. Local news, foreign-language outlets, blogs. Same as Tier 3: published with a "seeking 2nd source" badge until corroborated.

Pocket lifecycle

A pocket starts as reported. It moves to confirmed when a second independent source corroborates, or directly to verified when a primary agency publishes a statement. Pockets are resolved when patients have recovered or died and the case is officially closed. Pockets are retracted only when the original reporting source publishes a correction.

Update cadence

Live news feed updates every 20 minutes. Pocket counts and editorial events are entered manually by the editor against a primary source. The "Updated X minutes ago" timestamp on the dashboard reflects the most recent feed-ingest run, not the most recent editorial change to a pocket.

What we do not do

We do not estimate. We do not extrapolate. We do not aggregate counts across pockets when their case definitions differ. We do not retroactively edit a pocket without leaving a history entry.