Sources

Sources are materials from which information is obtained to support claims and establish the provenance of ideas. They can take many forms, including documents, datasets, images, recordings, and oral testimonies, and may be print or digital. The quality and relevance of sources affect the credibility of any work.

Sources are commonly categorized as primary, secondary, or tertiary. Primary sources provide original evidence or first-hand accounts, such as research reports, diaries, legal documents, or raw data. Secondary sources interpret or analyze primary materials, like review articles, scholarly books, or critical essays. Tertiary sources summarize secondary material, for example encyclopedias and bibliographies. Each type serves different purposes in research and citation.

Evaluating sources involves criteria such as authority (author qualifications and affiliation), accuracy (factual correctness and evidence), objectivity (lack of bias), currency (timeliness), and relevance to the topic. Provenance, methodological soundness, and corroboration by independent sources also matter. Accessibility and licensing influence how sources can be used, cited, and shared.

In practice, sources are used to support statements, contextualize findings, and trace the lineage of ideas. Proper citation attributes ideas to their creators and helps readers locate sources themselves. Researchers organize sources in notes and bibliographies, choosing a consistent citation style (APA, MLA, Chicago) and including essential details like author, title, publication data, and access information. For digital sources, it is important to record URLs and access dates and to consider issues such as link rot and copyright. Ethical and legal considerations, including fair use and data licensing, also guide source selection and use.