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Researching Statutes: Commentary

This guide serves as an introduction to statutory research. To access the linked databases on Westlaw and Lexis, you should sign on to Westlaw and Lexis before clicking on the links in this guide.


Before digesting the language of the statute and the meaning of that statute, it is often very rewarding to read the commentary in a particular area of law.  Because commentary sources digest the law for you, you will find it easier to grasp the law's meaning and the policies behind it. Also, commentary sources cite to the relevant case law, statutes, regulations and administrative rulings. This is particularly useful if you do not know the citation of a statute. A secondary source will provide you with that citation and will also describe and analyze the statute for you.   Listed below are a few main categories of commentary along with a description of each.  To access these materials, you can do a keyword search in SARA, the library's online catalog.

  • Treatises are a form of commentary which thoroughly analyze a legal subject.  Treatises typically contain three parts: the text itself; finding tools, such as a table of contents, index, or list of authorities; and supporting materials, such as an appendix of pertinent statutes/cases.  Treatises explain the law in detail, providing the rules, policies, and examples to illustrate those rules and policies. Sometimes treatises critique a particular law and offer legal reforms.
  • Looseleaf Publications are a special type of treatise that contain the text of the laws, regulations, cases, commentary on the relevant laws, as well as provide current awareness or news articles in that area of law. Looseleafs are called looseleafs because they are kept in three ring binders and are updated regularly by the adding or removing of looseleaf sheets to the binder. The three main looseleaf publishers are: BNA, CCH, and RIA.  To identify a relevant looseleaf publication in SARA, run a keyword search with the name of the publisher (for example, CCH and Trade).
  • Legal Encyclopedias cover a wide range of topics very broadly.  They are a useful starting point for a researcher who has little or no experience in a particular area of law. Each topic is organized into parts and sections.  Each sections contains text, which describe a particular issue, along with citations to cases, statutes, and regulations.  The two main legal encyclopedias are American Jurisprudence 2d, and Corpus Juris Secundum (CJS).  For New York law, the main legal encyclopedia is New York Jurisprudence 2d.
  • ALR Annotations, like legal encyclopedias, cover a wide range of topics.  Unlike legal encyclopedias, ALR Annotations describe a discrete topic in detail, digesting various relevant cases.  ALR Annotations are useful because the case descriptions are arranged by rule or key facts, making it easy to see how different jurisdictions approach an issue.  Also, ALR Annotations are very current; it is often the first secondary source to comment on a new topic.