It is important to know what kinds of resources exist, otherwise you may not know to look for certain kinds during your research. All information resources can be classified into three categories: primary, secondary, and tertiary. However, some resources can be placed in multiple categories. For example, a scholarly article that presents new, original research while discussing previous research, is both a primary and secondary resource.
Primary Resources
Definition: original work.
Examples: literature, poems, speeches, letters, memos, personal narratives, diaries, interviews, autobiographies, theses, dissertations, scholarly journal articles (research based), some government reports, and symposia and conference proceedings.
Secondary Resources
Definition: work that analyzes, summarizes, interprets, reorganizes, or otherwise provides an added value to a primary source.
Examples: books and articles that interpret or review research works, histories, biographies, literary criticism and interpretation, reviews of law and legislation, political analyses and commentaries, textbooks (may also be tertiary), edited works, dictionaries/encyclopedias (more often tertiary), and bibliographies (more often tertiary).
Tertiary Resources
Definition: source that indexes, organizes, compiles, or digests other sources.
Examples: dictionaries/encyclopedias (may also be secondary), almanacs, fact books, bibliographies (may also be secondary), directories, guidebooks, manuals, handbooks, and textbooks (may be secondary), indexing and abstracting sources.
