Referencing on Wikipedia
Why do I have to include a source for information I add to Wikipedia?
Unlike traditional encyclopedias, which gain legitimacy through their brand or the academic
credentials of their authors, Wikipedia must rely on the reliability of its information. Readers
must be assured that the information is not “made up.” One way of reassuring readers is by
pointing them to the ultimate source of the information, where they could verify the
information, if they so chose. Wikipedians are fond of saying that the threshold for inclusion in
the encyclopedia is “verifiability, not truth.” That is, we only include information that has been
published elsewhere by reliable sources that readers can verify themselves. Our policy thus
prohibits the publication of the opinions of individual Wikipedians.
Does every piece of information in a Wikipedia article have to be
sourced?
The more information that is sourced, the more legitimate the article becomes. However, citing
obvious facts that the average adult knows such as “William Shakespeare was a playwright”
leads to overcitation and confusion for the reader. Wikipedia policy (WP:Verifiability) requires
that “anything challenged or likely to be challenged…be attributed to a reliable source” using an
inline citation. In practice, the best Wikipedia articles cite more information than traditional
research papers. When in doubt, cite! All quotations, statistics, contentious statements about
living people, and extraordinary claims, must be cited. Statements claiming that a person was
“the first” or “best,” for example, demand a source. Thus, while the statement “William
Shakespeare was a playwright” does not require a citation, the statement “William Shakespeare
is the best playwright in the English language” does. A good rule of thumb to follow is that
every paragraph should have at least one citation.
What counts as a reliable source on Wikipedia?
Reliable sources are, as Wikipedia’s guideline on sourcing explains, “third-party, published
sources with a reputation for fact-checking and accuracy.” Choosing sources for an article
largely depends on the topic. As the guideline points out, “the appropriateness of any source
depends on the context.” However, the best sources are generally academic, peer-reviewed
publications, followed by university-level textbooks, books published by respected publishing
houses, magazines, journals, and mainstream newspapers. Any electronic media that meet the
same stringent criteria may also be used.
