Wikipedia:Two prongs of notability

Notability, our standard regarding whether a topic merits its own article, fundamentally has two prongs. A subject must be both worthy of our notice and also must have been noticed and received significant coverage in reliable secondary sources, in order for us to write an encyclopedia article on the topic.

Prong 1: Worthy of notice
The first prong of the notability test is whether a subject is worthy of our notice. A high school sports team will usually draw significant local coverage in independent reliable sources, but most of them are not noteworthy enough for an encyclopedia article. As well, some run-of-the-mill people, places, and things might draw significant coverage of a routine nature. Some of our subject-specific notability guidelines offer guidance for determining which things are worthy of our notice. For topics outside of the domain of subject-specific notability guidelines, the existence of coverage itself is taken as a presumption of being noteworthy. This presumption can be challenged and debated at articles for deletion, since coverage is an imperfect indicator of noteworthiness.

Prong 2: Has sources enabling encyclopedic treatment
"We require 'significant coverage' in reliable sources so that we can actually write a whole article, rather than half a paragraph or a definition of that topic. If only a few sentences could be written and supported by sources about the subject, that subject does not qualify for a separate page"

The other prong of notability ensures that we can actually write an encyclopedia article on a subject. The main thrust of the general notability guideline is that a subject has "significant coverage in reliable sources that are independent of the subject". This excludes things such as mere passing mentions, press releases, and self-published work. The general notability guideline is an adjunct to our policy of verifiability. If we lack sufficient secondary source coverage to build an encyclopedia article about a subject, we usually should not have an article on that subject, even if it was otherwise worthy of our notice. Our policy on self published sources states that they should not be the primary source of material for an article. Without secondary sources, it is impossible to include any critical analysis or serious discussion of a subject, since our policy on original research forbids us from drawing conclusions based on disparate primary sources.

Both required
Subjects that fail either prong of the test generally should not have stand-alone articles. Subjects that satisfy either prong individually, but not both, can sometimes be included as content in other articles.
 * Failing the first prong: Articles on subjects not worthy of notice work against the concept that Wikipedia is not an indiscriminate collection of information.
 * Failing the second prong: Subjects without sources enabling encyclopedic treatment can only ever have short stubs that are verifiable, that can likely never evolve into a proper encyclopedia article. These subjects are best treated as part of a larger article that can easily pass both tests when taken as a whole.

Articles that satisfy the second prong usually, but not always, satisfy the first prong as well. Some subject-specific notability guidelines specify that certain types of routine coverage should not be considered for notability purposes, even if they would otherwise satisfy the requirements for being a reliable source for an encyclopedia article.

Wikipedia is an encyclopedia
While we've focused a lot on what Wikipedia is not, in the end, we are supposed to be an encyclopedia. An encyclopedia article is supposed to be detailed and comprehensive. This is contrasted with other sorts of reference works such as a dictionary, a book of statistics, or a Who's who type book. When we allow topics that fail one prong or the other, we stray from our mission of being an encyclopedia.

Biographies
Sometimes a person has clearly made an impact in their professional field (as evidenced by numerous citations or a prestigious award, for example), but there is little or no independent, biographical, coverage of them available. We usually should not have standalone biographies on these people. Lacking independent, biographical, coverage of the person, we are unable to construct an encyclopedic biography for them. Sometimes these people have self-published biographies, resumes, or CVs on their personal or professional web site. Our policy prohibits writing an article primarily based on these self-published sources.

Such biographies based primarily on self-published information will almost never include any negative or critical information about the subject. The foundation has issued guidance identifying overly promotional biographical articles for living people as a core issue facing Wikipedia, and has declared that they "are not neutral, and have no place in our projects." Such biographies should be deleted if no reliable, independent sources of biographical information about the person (and not their work) can be found.

Notable work, of course, may be included in the relevant subject matter articles for that field, and may even merit its own article. A stand-alone biography should be a biography, not a directory of a person's work. A highly cited academic work, for example, might merit an article of its own, even if its author does not due to a lack of independent biographical coverage.

Places, roads, infrastructure
Wikipedia has a traditionally accepted a role as a gazetteer, which effectively exempts many public places, roads, towns, and the like from being subject to questions regarding noteworthiness. This consensus is subject to change, but is fairly well established, and not often challenged.