Wikipedia:Independent sources

In determining the type of source, there are three separate, basic characteristics to identify:

This page deals primarily with the second question: identifying and using independent and non-independent sources.

Independence does not imply even-handedness. An independent source may hold a strongly positive or negative view of a topic or an idea. For example, a scholar might write about literacy in developing countries, and he may personally strongly favor teaching all children how to read, regardless of gender or socioeconomic status. Yet if the author gains no personal benefit from the education of these children, then the publication is an independent source on the topic.

Material available from sources that are self-published, primary sources, or biased because of a conflict of interest can play a role in writing an article, but it must be possible to source the information that establishes the subject's real-world notability to independent, third-party sources. Reliance on independent sources ensures that an article can be written from a balanced, disinterested viewpoint rather than from the person's own viewpoint. It also ensures articles can catalogue a topic's worth, its role and achievements within society, rather than offering a directory listing or the contents of a sales brochure.

Articles that don't reference independent sources should be tagged with {{}}, and if no substantive coverage in independent reliable secondary sources can be identified then the article should be nominated for deletion. If the article's content is strictly promotional, it should even be made a candidate for speedy deletion under criterion WP:CSD G11.

These simple examples need to be interpreted with all the facts and circumstances in mind. For example, a newspaper that depends on advertising revenue might not be truly independent in their coverage of the local businesses that advertise in the paper.

This concept is contrasted with the unrelated concept of a secondary source, which is one where the material presented is based on some other original material, e.g., a non-fiction book analyzing original material such as news reports, and with a primary source, where the source is the wellspring of the original material, e.g., an autobiography or a politician's speech about his or her own campaign goals. Secondary does not mean third-party, and primary does not mean non-independent or affiliated with the subject. Secondary sources are often third-party or independent sources, but they are not always third-party sources.

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