News Credibility Score

How WorldMonitor scores per-headline source reliability separately from newsworthiness — source tier, propaganda risk, independent corroboration, and the state-media cap.

Start here

Every headline in WorldMonitor carries two separate numbers, and keeping them separate is the entire idea.

Importance asks: how much does this matter right now? Credibility asks: how much should I trust this source on this story?

A state-controlled outlet breaking real news about its own government’s military movements is highly important and poorly credible at the same time. Most news tools collapse that into one ranking and force you to choose between missing the story and trusting the source. WorldMonitor shows you both numbers and lets you decide.

What credibility is built from

Ingredient	Weight	The question behind it
Propaganda risk	0.50	Does this outlet answer to a government or an interest with a stake in the story?
Source tier	0.30	What is this outlet’s track record?
Independent corroboration	0.20	Is anyone unconnected reporting the same thing?

Note what is absent. Severity, recency, and how dramatic the event is carry no weight here at all — those belong to importance. Only things that bear on truthfulness are allowed to move this number.

State media is capped, not banned. An outlet under state control cannot reach a high credibility score no matter how many others repeat it — because repetition inside a controlled media environment is not independent corroboration. It stays visible and readable, with an honest label on it.

No human sits in this loop

The pipeline is automated end to end. Quality comes from a curated source-tier table, a fail-closed propaganda-risk registry, and corroboration counts the digest already computes. Third-party bias ratings (AllSides, MBFC) are deliberately not applied today.

For developers. The field is credibilityScore on NewsItem, served from GET /api/news/v1/list-feed-digest (proto worldmonitor.news.v1.NewsItem.credibility_score).

How it differs from importance

Score	Question	Typical high scorer
importanceScore	How newsworthy is this right now?	A critical RT flash on a diplomacy/flashpoint event
credibilityScore	How much should I trust this source on this story?	The same story reported by Reuters

A state-controlled outlet can score high on importance and low on credibility at the same time. That split is the product, and mixing the two is the flaw a sophisticated buyer finds first.

Inputs

Only inputs that bear on truthfulness enter the score. Severity, recency, and the diplomacy/flashpoint boost stay on importanceScore.

Component	Weight	Source
Propaganda risk	0.50	shared/source-provenance.ts SOURCE_PROPAGANDA_RISK
Source tier	0.30	shared/source-tiers.json
Independent corroboration	0.20	Digest story-identity / entity corroboration count

Weights sum to 1.0. The implementation is shared/news-credibility.js (computeCredibilityScore). The digest writes the field after classification and corroboration, alongside — not instead of — importanceScore.

Component Maps

Source tier maps to:

Tier	Score	Meaning
1	100	Wire / official
2	75	Major established outlet
3	50	Specialty / regional
4 (default)	25	Aggregator, blog, or unlisted feed

Propaganda risk maps to:

Risk	Score	Meaning
low	100	Reviewed independent journalism
medium	50	State-affiliated or known editorial tilt
unknown	35	Not yet reviewed — fail-closed, never treated as independent
high	12	State-controlled media

Unlisted sources default to unknown, not low. That fail-closed default is the same contract as the provenance badges.

Independent corroboration uses the digest’s existing corroboration count (the larger of story-identity cluster size and entity-level corroboration), capped at five sources, with 20 points per source before the 0.20 weight. This is the same corroboration signal importanceScore already consumes; it is not a second clustering pass.

High-Risk Cap

After the weighted sum is rounded and clamped to 0–100, a source whose propaganda risk is high is capped at 40.

The cap is the acceptance gate for state media. An RT or TASS item can still pick up corroboration points when independent outlets also report the event, but it cannot look like a high-credibility wire. Reuters with no extra corroboration scores around 80; RT with none scores in the low 20s.

What This Score Is Not

• It is not a statement that the underlying event is false. A true event reported first by state media still has low source credibility until independent outlets corroborate it.
• It is not AllSides or MBFC. Those ratings are out of scope until a dedicated ingest exists.
• It is not used to sort the news list. Relevance sort remains importanceScore, then publication time. Credibility is displayed, not substituted for newsworthiness.
• Same-ecosystem inflation remains a known limitation: five Russian state desks clustering on one headline still share one high-risk cap, but the corroboration count is the digest’s existing publisher-family signal, not a new independence classifier.

Surfaces

Surface	Field
Feed digest API	NewsItem.credibilityScore
News list UI	CRED NN badge on flat items and clustered cards
Insights / MCP get_news_intelligence	topStories[].credibilityScore
MCP get_news_clusters	clusters[].credibilityScore for the primary outlet

Source Files

• Scorer: shared/news-credibility.js
• Digest writer: server/worldmonitor/news/v1/list-feed-digest.ts
• API contract: proto/worldmonitor/news/v1/news_item.proto
• Provenance registry: shared/source-provenance.ts
• Tier table: shared/source-tiers.json
• News list render: src/components/news/source-provenance.ts, src/components/NewsPanel.ts
• Pipeline sibling: News Digest and Briefing