Secondary Sources Research Guide

This guide explains various types of secondary sources, including legal encyclopedias and American Law Reports, and how to use them.


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What is a Legal Encyclopedia?

A legal encyclopedia is a comprehensive set of brief articles on legal topics. It is arranged similarly to a general encyclopedia, such as Encyclopedia Britannica, with topical articles arranged in alphabetical order. In the final volume(s) of most legal encyclopedias is an index. The two most popular general legal encyclopedias are Corpus Juris Secundum (C.J.S.), and American Jurisprudence, 2d (Am. Jur. 2d). In addition, there are numerous state legal encyclopedias, as well as encyclopedias with a more narrow focus, such as American Jurisprudence Trials

Why Use a Legal Encyclopedia?

There are two primary uses for legal encyclopedias.

First, the articles can be quite useful as a general introduction to an area of law which is new to you. They provide more in-depth information than a legal dictionary, while being nearly as accessible and easy to use.

Second, encyclopedias are a way to find citations to cases and other useful materials on a particular issue. These two uses make the encyclopedias a very good place to begin major research, whether for an academic paper or a legal memorandum. However, the legal encyclopedias are not intended to be used as authoritative sources on the law in any area, and thus are not cited in briefs, memoranda, or scholarly papers.

Using a Legal Encyclopedia

Using a legal encyclopedia is straightforward: look up your topic in the index (look for the volumes at the end of the set if you're researching in print), identify the section or sections where your topic is discussed, turn to those sections, and read them. At the beginning of each major topic, you will find two outlines of what is covered in the article: first, a broad general outline, and second, a very detailed outline. These outlines may be useful for placing your specific topic in context. At the beginning of each entry you will also find a note on "scope," indicating what will be covered in the article, and what will be treated elsewhere. This is worth reading, to be sure your particular issue is not covered better in a separate article. Following these preliminary materials is the text of the topical discussion.
The articles and footnotes are updated (look at the pocket parts found in each volume if you're researching in print). In addition to these standard features, each encyclopedia has its own unique features. Because of these differences, you may begin to prefer one encyclopedia over the other in certain circumstances. However, when beginning major research, it is a good idea to consider using both.

Am. Jur. Features

American Jurisprudence's methodology is selective, in contrast to C.J.S.'s comprehensiveness. This means that Am. Jur. provides citations only to the cases the editors consider the best or most important. This results in shorter footnotes, adding to the readability of Am. Jur.'s articles. In addition, this set of encyclopedias is more likely to cover important federal statutory material.

For online access:

C.J.S. Features

Articles in Corpus Juris Secundum tend to be longer and more detailed than American Jurisprudence articles. Because C.J.S.'s goal is to provide the researcher with every relevant citation, you will see some pages which have more footnotes than actual text. Second, C.J.S. will tend to give you citations to mostly cases, and fewer statutes. If there is an appropriate topic and key number for your subject, C.J.S. will also provide these. Thus, C.J.S. will be helpful in getting you ready to use the various West digests. (See Digests, Headnotes, and Key Numbers on the Case Law Research Guide for more on using digests.) 

For online access:

To find state or other specific encyclopedias in print or available online, check our state research guides or search the Law Library's catalog. State encyclopedias are found within the individual state's materials in our State Collection on the first floor

Encyclopedias Tutorial

Running time: 3:16 minutes

Created/updated: August 2023
Last reviewed: August 2023