Template:Tertiary source

Whereas a primary source presents material from a first-hand witness to a phenomenon, and a secondary source provides commentary, analysis and criticism of primary sources, a tertiary source is a selection and compilation of primary and secondary sources. Typical instances of tertiary sources are bibliographies, library catalogs, directories, reading lists and survey articles.

While the distinction between primary source and secondary source is essential in historiography and originates there, the distinction between these sources of evidence and tertiary sources is not so relevant, and appears to originate in library science.

Encyclopaedias and textbooks are examples of materials that typically straddle both secondary and tertiary sources, both presenting commentary and analysis, while attempting to provide a synoptic overview of the material available on the topic. For instance, the long articles of the Enclyclopaedia Britannica certainly constitute the kind of analytical material characteristic of secondary sources, whilst also attempting to provide the kind of comprehensive coverage assocaited with tertiary sources.