Primary, secondary, and tertiary sources[edit]

All articles should rely on reliable, third-party published sources with a reputation for fact-checking and accuracy.WP:SourcesThough we may report the attributed opinions of reliable authors, articles should never include the opinions of Wikipedians themselves, even if you are an expert who has read any number of primary, secondary, or tertiary sources.

Youropinions and interpretations do not belong in an article. But it is appropriate to documentinterpretationsof events, data, or opinions, as published in reliablesecondary sourcematerial. Peer-reviewed sources are especially valued. Whilesecondary sourcematerial is most preferred,primary sourcesmay also be used to report factual material provided the contributing editor states the fact in a manner that does not present an interpretation of the fact (original research) which is not itself explicitly contained in the primary source.

The question of whether source material is secondary or primary should not, however, become a focal point for edit warring. Proper classification of sources can be complex because different definitions apply in different fields of knowledge. In addition, a single source may contain both primary and secondary material. For example, a peer-reviewed science article including original findings may include a scatter plot of data points and a cross-sectional x-ray (primary material), but it may also include valuable secondary material, such as the research team's synthesis and interpretation of prior published studies reviewed in the discussion of the results or as background for why the study was conducted.

Similarly, a 1863 newspaper about the Gettysburg Address may include secondary source quotes from text of the Address (the primary source being Lincoln's manuscript), but it would be a primary source of any commentary or observations about the Address. It might also include tertiary material if the reporter included a summary of written reports that appeared in other newspaper accounts.

The classification of a source may also vary depending on use. The same 1863 newspaper articles about Lincoln's speech become primary sources when used by a modern scholar to write a dissertation on media treatment and public reactions to Lincoln and the Civil War.

Because of these many variables, there is a grave risk that arguments about how a source should be classified can become occasions for unproductiveedit warringandwikilawyering.

It is therefore important to remember that, according to policy, primary, secondary, and tertiary sources may all be acceptableif used appropriately.Therefore, how material is classified is far less important than making certain that the material cited from the source is accurately describedwithout inserting interpretations which are not specifically present in the cited source.That is the essence of the "No Original Research" policy.

For additional information regarding classification of source material, with examples regarding the appropriate use or misuse of these sources in Wikipedia, please seePrimary Secondary and Tertiary Sources.

NOTE: The following section would not be included in NOR policy. It would be a separate page offering guidelines.

Start of guidelines regarding use of primary, secondary and tertiary sources [edit]

According to Wikipedia'sverifiabilitypolicy, any material that is challenged or likely to be challenged must be accompanied by areliable source. In general, the most reliable sources are (a) peer-reviewed journals and books published in university presses, followed by (b) university-level textbooks; then by (c) magazines, journals, and books published by respected publishing houses; then by (d) mainstream newspapers.

Research that consists of collecting and organizing material from existing sources is encouraged: this is "source-based research," and it is fundamental to writing an encyclopedia. Problems often arise, however, when editors use sources in ways that constituteoriginal research, or which violate Wikipedia'spolicy of neutrality.

This guideline sets factors that an editor should keep in mind while using various types of sources for verifying the statements in an article. Sources can be classified in various ways. The most useful classification is by theirprimary,secondaryortertiaryin nature. Another classification is in terms offirst-partyorsecond-party.

Primary, secondary, and tertiary sources may all be appropriately used, if (1) they are used without engaging in original research or synthesis and (2) if in the event of conflicts between sources they are treated with the appropriate deference to the "better" source. These guidelines address these two principles.

The classification of primary, secondary, and tertiary sources can be different in various disciplines and may depend on the context in which the source is used. The examples and definitions given in these guidelines are provided as an aid for more informed discussion of these classification issues when they come up.

Primary sourcesare sources very close to the origin of a particular topic or event. An eyewitness account of a traffic accident is an example of a primary source. Other examples include archeological artifacts; photographs; videos; historical documents such as diaries, census results, maps, or transcripts of surveillance, public hearings, trials, or interviews; unstipulated results of surveys or questionnaires; the original written or recorded notes of laboratory and field research, experiments or observations which have not been published in a peer reviewed source; original philosophical works, religious scripture, administrative documents, patents, and artistic and fictional works such as poems, scripts, screenplays, novels, motion pictures, videos, and television programs.[1]

Secondary sourcesare accounts at least one step removed from an event or body of primary-source material and may include an interpretation, analysis, or synthetic claims about the subject.[2]Secondary sources may draw on primary sources and other secondary sources to create a general overview; or to make analytic or synthetic claims.[3][4]

Tertiary sourcesare publications such as encyclopedias or othercompendiathat sum up secondary and primary sources. For example, Wikipedia itself is a tertiary source. Many introductory textbooks may also be considered tertiary to the extent that they sum up multiple primary and secondary sources.