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Reference Sources: Encyclopedias

A guide on the types of reference sources


Encyclopedias are often called tertiary sources, but sometimes they can be secondary sources or primary sources. They compile information from trusted experts and produce short entries on each item. Tertiary sources provide you with basic information that you might need to proceed with your project, and they can help you narrow your research question. They often point you towards the secondary and primary sources you need for research projects.

When you begin a research project, it is helpful to have a good overview of your topic--especially if it is one that is new to you. Encyclopedias are sources that include basic overviews of topics or subjects; definitions of terms specific to a field of study; provide visual images such as maps, charts and graphs, or they provide primary documents that reveal the extent of the problem. In Research Strategies: Finding Your Way through the Information Fog, William Badke explains that you have acquired a "working knowledge" of a subject "when you can talk about it for one minute without repeating yourself" (49). When reading an encyclopedic entry, try to discover:

  • a definition of your topic (what)
  • its time period (when)
  • the main people or organizations involved (who)
  • the location (where)
  • the causes behind it (why)
  • actions taken regarding it (how)

Types: There are two types of encyclopedias: General and Subject. General encyclopedias provide brief overviews on many different topics. Subject encyclopedias provide more details on important dates, people, and events on a topic.

Characteristics: Entries are written (signed) by an expert or scholar in the field; provide references or bibliographies for further research; cross-reference other topics of similar interest; published in single or multi volume sets.

Locating encyclopedias: From the library's home page, type in your topic keyword (or keyword phrase) and include the keyword encyclopedia in the search box


The results will be all of the encyclopedias in the collection on the global warming in print and/or electronic formats.

Citations:  Follow the style guidelines for creating your citations.  Please see APA Style Guide, MLA Style Guide, or Chicago/Turabian

Examples: Below are examples of different types encyclopedias from the library's collection.


Anatomy of an encyclopedia entry

This example shows an entry in an encyclopedia that is written by one person--the author of all the content within the encyclopedia.


An encyclopedia that has an editor and other contributors writing the chapters/articles may look like any other entry.

entry for Clogs in encyclopedia


The difference is each chapter/article will list the name of the contributor. Go to the Contributors list to find out more on the author, such as education or expertise on the subject.