Defining Fact-Checking

Fact-checking is the systematic process of investigating and evaluating the veracity of factual claims made by public figures, media organisations, political actors, and others in public discourse. The practice involves identifying a specific checkable assertion, locating authoritative evidence, and rendering a verdict that is published transparently with full sourcing.

Fact-checking operates in two distinct modes: pre-publication fact-checking, in which editors verify claims before they appear in print or broadcast, and post-publication fact-checking, in which independent organisations assess public claims after they have circulated. Both modes are essential components of a healthy information ecosystem.

The History of Organised Fact-Checking

Organised political fact-checking emerged in the United States in the early 2000s. FactCheck.org, operated by the Annenberg Public Policy Center at the University of Pennsylvania, launched in 2003 as the first dedicated political fact-checking website. PolitiFact followed in 2007, introducing the now-iconic "Truth-O-Meter" rating scale. The Washington Post's Fact Checker column, with its Pinocchio ratings, launched in 2011.

The field expanded globally following the 2016 US presidential election, during which concern about misinformation's electoral impact drove significant investment in fact-checking infrastructure. By 2024, the Duke Reporters' Lab tracked more than 400 active fact-checking organisations in over 100 countries.

Fact-Checking Methodology: How Professional Checkers Work

Professional fact-checkers follow a standardised methodology with six core steps:

  1. Claim selection: Identify specific, verifiable factual assertions — distinguishing them from opinions, predictions, and rhetorical questions that cannot be objectively assessed.
  2. Claim transcription: Quote the exact claim as stated, with full context including speaker, date, and platform. Misquoting the claim is a fundamental error in fact-checking.
  3. Evidence gathering: Consult primary sources — official statistics, peer-reviewed research, court documents, financial filings, and authoritative expert testimony. Avoid relying on secondary sources that themselves have not been independently verified.
  4. Expert consultation: For technically complex claims (scientific, economic, medical), consult domain experts who can assess whether the evidence supports the claim.
  5. Subject notification: Contact the person or organisation that made the claim to allow them to provide supporting evidence or clarify their statement before the verdict is published.
  6. Verdict and publication: Render a verdict using a standardised scale (True, Mostly True, Half True, Mostly False, False, Pants on Fire) with full sourcing and transparent methodology.

The Role of AI in Modern Fact-Checking

AI has transformed the scale and speed of fact-checking without replacing its essential human elements. AI tools now assist with claim detection (identifying which statements in a speech or article warrant checking), preliminary research (rapidly searching large corpora for relevant evidence), translation (enabling fact-checkers to verify claims in foreign-language sources), and monitoring (continuously tracking the spread of previously debunked claims across platforms).

Omniscient AI's Chrome extension enables users to fact-check any web page in real time, using three AI models to retrieve evidence from 1,200+ curated sources. This democratises professional-grade fact-checking, making it accessible not just to dedicated fact-checking organisations but to any journalist, researcher, student, or engaged citizen.

Standards and Accreditation

The International Fact-Checking Network (IFCN), housed at the Poynter Institute for Media Studies, operates the global accreditation standard for professional fact-checking organisations. To receive IFCN certification, an organisation must adhere to five principles: commitment to nonpartisanship and fairness; transparency of sources; transparency of funding and organisation; transparency of methodology; and open and honest corrections policy. As of 2025, more than 120 organisations in 60+ countries hold IFCN certification.