A Wikipedia article cannot establish the truth about its subject, but it must truthfully report the available knowledge on the subect. Uncertain statements must be qualified as such, and subjective claims attributed to their authors.
Note that while truthfulness of the article text is required to achieve NPOV, the articles also need to be complete and balanced.
Truthfulness is ensured by writing only statements that are true beyond reasonable doubt. To achieve this, the following techniques are used:
Reporting of known facts without qualification[edit]
Statements about the subject which are believed to be true beyond reasonable doubt may be made in the article without qualification or textual attribution. They still need to be sourced to a reliable source.
Widely reported events
The last outbreak of smallpox in Europe happened in 1972.
Abba went on a tour of Australia in 1977.
Facts by definition
Avogadro constant is the number of atoms in exactly 12 grams of 12C.
France is a republic.
Matters of official record
The Conservative party won UK parliamentary elections in 1992.
The PATRIOT Act was adopted in October 2001
Geographical and astronomical facts
Adriatic sea lies between the Italian and Balkan peninsulas.
The Moon is a satellite of the Earth.
Mathematically proven facts
The circumference of a circle is larger than its diameter.
Scientific claims which are universally or near universally accepted as known facts in the appropriate discipline
AIDS is cause by HIV.
Silicon and aluminium are the most common elements in the Earth crust.
Things that can be qualified as uncertain, without textual attribution[edit]
Claims that are widely considered to be most likely true, but not certain.
Scientific theories which are universally or near universally accepted as the best available theory in the appropriate discipline, but considered uncertain or unknowable.
Wrong: The Moon was created when the Earth collided with its sister planet.
Correct: It is thought that the Moon was created when the Earth collided with its sister planet.
Reconstructions of events which are universally or near universally accepted as the most likely explanation, but considered uncertain or unknowable.
