What counts as a reliable source?
The word "source" in Wikipedia has three meanings:
* the type of the work (some examples include a document, an article, or a book)
* the creator of the work (for example, the writer)
* the publisher of the work (for example, Oxford University Press).
All three can affect reliability.
Base articles on reliable, third-party, published sources with a reputation for fact-checking and accuracy. Source material must have been published, the definition of which for our purposes is "made available to the public in some form". Unpublished materials are not considered reliable. Use sources that directly support the material presented in an article and are appropriate to the claims made. The appropriateness of any source depends on the context. The best sources have a professional structure in place for checking or analyzing facts, legal issues, evidence, and arguments. The greater the degree of scrutiny given to these issues, the more reliable the source. Be especially careful when sourcing content related to living people or medicine.
If available, academic and peer-reviewed publications are usually the most reliable sources, such as in history, medicine, and science.
Editors may also use material from reliable non-academic sources, particularly if it appears in respected mainstream publications. Other reliable sources include:
* university-level textbooks
* books published by respected publishing houses
* mainstream newspapers.
Sources that are usually not reliable
Questionable sources are those that have a poor reputation for checking the facts, lack meaningful editorial oversight, or have an apparent conflict of interest. Such sources include websites and publications expressing views that are widely considered by other sources to be extremist or promotional, or that rely heavily on unsubstantiated gossip, rumor or personal opinion. Questionable sources should only be used as sources of material on themselves, especially in articles about themselves.
Anyone can create a personal web page or publish their own book, and also claim to be an expert in a certain field. For that reason, self-published media, such as books, patents, newsletters, personal websites, open wikis, personal or group blogs (as distinguished from newsblogs), Internet forum postings, and tweets, are largely not acceptable as sources. Self-published expert sources may be considered reliable when produced by an established expert on the subject matter, whose work in the relevant field has previously been published by reliable third-party publications.
In Wikipedia, The Free Encyclopedia. Retrieved 10:15 January 15, 2015, from http://en.wikipedia.org/wiki/Wikipedia:Verifiability#Reliable_sources