ClaimReview

The exact textual statement being fact-checked. This property holds the claim itself, not a summary or paraphrase. For accurate entity extraction, the claim should be a short, self-contained assertion.

• Best practice: Quote the claim verbatim as it appeared in the original source.
• Example: "The Earth is flat and stationary."
• Critical for: Enabling search engines to match the fact-check to the original claim across the web.

The veracity assessment of the claim, expressed as a Rating type. This is the core output of the fact-check, communicating the truthfulness of the claimReviewed.

• Standardized values: Use a defined scale like True, False, Mostly True, Mixture, or custom ratings.
• Best practice: Always include both ratingValue (the text label) and alternateName (a short human-readable version).
• Example: "ratingValue": "False" with "alternateName": "Pants on Fire".

The Organization or Person that conducted the fact-check and published the assessment. This property establishes the credibility and authority of the review.

• Must be an entity: Link to an Organization schema with a name, url, and ideally a sameAs reference to a Wikidata or Wikipedia entry.
• Transparency signal: Search engines use this to determine if the fact-checker is a verified, trusted source.
• Example: "author": {"@type": "Organization", "name": "Snopes.com", "url": "https://www.snopes.com"}.

The CreativeWork (article, social media post, video) that contains the claim being fact-checked. This property contextualizes the claim by linking it to its source material.

• Nested entity: Use a CreativeWork type with properties like author, datePublished, and appearance (the URL where the claim appeared).
• Distinction: itemReviewed is the container of the claim; claimReviewed is the specific assertion within it.
• Example: A viral Facebook post containing a false statistic would be the itemReviewed.

The canonical URL of the full fact-check article. This is the permanent link where users can read the complete analysis, methodology, and evidence behind the rating.

• Required for rich results: Google requires this to display the fact-check label in search results.
• Best practice: Ensure the URL is a dedicated, non-paginated page with the full fact-check content.
• Critical for: Driving traffic to the authoritative source and enabling users to verify the assessment independently.

The ISO 8601 date when the fact-check was first published. This temporal marker is critical for assessing the freshness and relevance of the review.

• Format: "2024-11-15T08:00:00+00:00"
• Why it matters: A fact-check of a rapidly evolving news story may become outdated. Search engines prioritize recent reviews for current claims.
• Best practice: Update this date only if the fact-check is substantively revised, not for minor typo fixes.

Algorithmic evaluation of the quality, relevance, and trustworthiness of a source cited by an AI or used in a fact-check. A high score strengthens the authority of a ClaimReview.

• Source Reputation: Historical accuracy and editorial standards
• Contextual Relevance: How directly the source addresses the specific claim
• Recency: Timeliness of the evidence for evolving topics
• Consensus Alignment: Agreement with other high-integrity sources

Anchoring the ClaimReview and its reviewed claim to deterministic facts stored in a structured knowledge graph. This prevents AI models from treating a debunked claim as valid.

• Fact Storage: Storing the verified claim and its rating as a graph edge
• Inference Prevention: Blocking hallucinated connections to false data
• Temporal Tracking: Maintaining a history of claim status changes over time

The mechanisms by which an AI system explicitly cites the origin of specific claims in its output. ClaimReview provides the machine-readable structure for these citations.

• Provenance Chains: Linking an AI's output back to the original fact-check
• Transparent Snippets: Displaying the author and reviewRating to end-users
• Trust Signals: Using the markup to visually badge verified information in search