Wikipedia:List of hoaxes on Wikipedia

This is a list of known historical hoaxes created on the English Wikipedia. It is not for known hoaxes which are notable in their own right, such as the Piltdown Man. Its purpose is to document hoaxes on Wikipedia, in order to improve our understanding of them and our ability to detect them. For the purpose of this list, a hoax is defined as a clear and deliberate attempt to deceptively present false information as fact. Libel, vandalism, and honest factual errors are not considered hoaxes. A hoax is considered notable enough for inclusion in this list if it evaded detection for more than one month or was discussed by reliable sources in the media. This list is incomplete, as many hoaxes remain undiscovered.

Hoaxes can be added to this page if they meet the requirements above. Do not list Wikipedia April Fools' Day pranks or factual articles about encyclopedically notable hoaxes. Start/Deletion date and Length are the dates and approximate time the article was generally visible.

For many of the below hoaxes, you can see an archived version of the deleted article by clicking on its title (see also list of archived hoaxes). Some also remain available from mirror sites. Any administrator can create an archived version of a hoax upon request by following the instructions below.

Academic research has investigated the impact and characteristics of Wikipedia hoaxes, and has proposed automated methods for detecting them. Researchers found that the automatic classification system was better at identifying hoaxes on Wikipedia than humans (86% vs. 63% accuracy) and used their algorithm to identify previously undiscovered hoaxes like "Steve Moertel" which went undetected for almost 7 years.^[2]One way to identify hoax articles included examining the article structure and content, its mentions in other articles on Wikipedia (i.e., embeddedness), and features of the editor who created the page. Specifically, hoax articles are likely to be longer than a legitimate article, less likely to have links to other Wikipedia articles, references, images, or other "wiki-like" markup, less likely to be mentioned in other Wikipedia articles before its creation, and more likely to be created by a new account with few to no other edits.^[2]

While most hoaxes on Wikipedia are short-lived (89% of discovered hoaxes are flagged within one hour of creation and only 1% of hoaxes persist for more than a year), those that make it past this initial screening have an increased probability of continuing to "survive" and remain a part of Wikipedia for much longer (if a hoax survives past its first day, it has an 18% probability of lasting for a year or more). Compared to unsuccessful hoaxes, successful hoaxes that survive for long periods of time are more likely to include some "wiki-like" mark-up and more likely to include links to other articles on Wikipedia.^[2]

Compared to legitimate articles, successful hoaxes generally receive less daily traffic, have a longer median article length (134 versus 71 words), and include fewer links to other Wikipedia articles when considering their article length.^[2]