Secondary sources are well-reasoned, explanatory statements about the law that provide commentary and/or analysis. They discuss the law, but they are not the law. Secondary sources such as legal encyclopedias, treatises, law review articles, ALRs, and restatements of the law are a great place to start your research. They can help you become familiar with an area of law, provide background information, and provide you with citations to relevant primary authority (case law, statutes, regulations). You will find more detail about each type of secondary source in the information presented below.
To locate secondary sources that may be helpful for your research consult with a reference librarian, search the library catalog for the resources listed below, review another of our research guides, or use a research guide available on the web several of which are highlighted within this guide.
The chart below provides some pros and cons of using each type of secondary source discussed in further detail below, which can be helpful for determining when to use which particular type of secondary source in your research.
Excerpted from Beau Steenken & Tina Brooks, Sources of American Law: an Introduction to Legal Research, Fifth Edition, published by CALI eLangdell Press, this chart is available under a Creative Commons BY-NC-SA 3.0.
Legal dictionaries provide definitions of legal vocabulary. They are helpful for broadening your understanding of the legal terms you encounter and their definitions can be cited in memos and briefs. By far, the most widely used legal dictionary is Blacks Law Dictionary, pictured to the right. Currently in its 11th edition, Black's is available in print in the library and on Westlaw. A shorter alternative to Black's is Ballentine's Law Dictionary, which is also available in print and on Lexis.
Prince's Dictionary of Legal Citations is a very helpful resource for deciphering unfamiliar legal abbreviations, acronyms, and citations. Prince's is available in print in the library; however, it is not available electronically.
While not a traditional dictionary, Words and Phrases, contains judicial definitions of various words and phrases used in court opinions from both state and federal courts. Words and Phrases is available on Westlaw.
Legal encyclopedias provide a broad overview of the law on a variety of subjects. Arranged alphabetically, they include narrative exposition of the topics covered along with citations to primary and other secondary authorities. When it comes to the jurisdiction covered by legal encyclopedias, they can be national in scope like American Jurisprudence (Am Jur) currently in its second edition (Am Jur 2d) and Corpus Juris Secundum (CJS) or they can be state-specific like Texas Jurisprudence (Tex Jur) currently in its third edition (Tex Jur 3d). Legal encyclopedias are available in print and electronically on Lexis and Westlaw.
Legal treatises provide in-depth analysis and narrative explanation of a single area of law, such as bankruptcy or copyright. They can range from comprehensive, multi-volume sets to concise, focused one-volume titles. Often written by influential legal scholars, there are some “gold-standard” treatises that are generally very well-respected and often cited to courts.
Legal treatises are regularly available both electronically and in print. In order to find a treatise relevant to your research, consult with a reference librarian, search the library catalog, review our collection of research guides on various subjects, or consult a useful treatise finder such as the one created by Michigan's Law Library or Harvard's Law Library.
Law reviews are student-edited academic journals that contain scholarly articles written by law professors as well as law students and sometimes practitioners. Law review articles provide in-depth analysis and intellectual discussion of legal issues and policy. These articles are heavily footnoted, thus providing citations to the seminal cases, statutes, and regulations on the subject of the article. The footnotes may provide citations to other relevant secondary sources.
Law review articles, and other legal periodicals like bar journal articles, are available electronically via HeinOnline, Lexis, and Westlaw. In order to locate relevant articles, you can use the search function in these databases or you can also use a legal periodical index such as Index to Legal Periodicals (ILP), which is available through the law library's electronic resources. Legal periodical indexes generally contain more information relating to older articles than other databases.
American Law Reports (ALR) is a secondary source that contains articles called “annotations.” These annotations are essays that provide a detailed description of the current state of the law on a narrow legal topic based on the federal and state case law that has addressed the issue. ALR annotations often cover matters that represent emerging, unsettled, or changing areas of the law or legal issues. Because these annotations explore the law in the jurisdictions that have dealt with the issue, ALR is often referred to as a “case finder.” ALR is available electronically on Westlaw and Lexis.
Restatements of the Law consist of succinct, highly regarded statements of “black letter” common law. Written by the American Law Institute (ALI), a prestigious organization of noted law professors, attorneys, and judges, Restatements are designed to reflect the consensus of the American legal community regarding what the law is, and in some cases, what it should become. Courts often cite Restatements, at times explicitly adopting the cited principle as their common law. Restatements of the Law are available in print in the library and electronically via HeinOnline, Lexis, and Westlaw.