What are secondary materials as a source of law?
In legal research, one can use primary and secondary sources of law. Primary sources are statements of law from a court, legislature, or executive like a president or governor. These sources can include court decisions, the U.S. Code or Code of Federal Regulations, the text of legislative bills, laws, or statutes already on the books, or other legal documents such as contracts.
In contrast, secondary sources are supplemental materials which explain, discuss, analyze, and interpret the law. Examples of secondary law sources include legal news articles, law reviews, legal reference books such as encyclopedias or dictionaries, legal articles, or legal books. These secondary sources can range from a restatement or an extensive analysis of a particular primary source. Of particular importance is the fact that where primary sources have binding authority, secondary sources do not, even though they may serve to influence a primary source.
There are a number of secondary legal sources, each of which has specific functions. First, legal dictionaries provide definitions of legal words and legal-related Latin words and phrases. Black’s Law Dictionary is a popular secondary legal dictionary. Legal encyclopedias such as American Jurisprudence and Corpus Juris Secundum are another type of secondary source that provides broad commentary on a number of federal and state laws and are highly recommended as a starting point for subsequent research, particularly concerning unfamiliar legal areas. Third are legal periodicals which provide articles that may explain new topics, comment on the current state of laws, and provide in-depth analysis on particular cases or issues. Legal periodicals are typically law school journals, bar association journals, and trade newsletters. Fourth are annotated law reports which focus upon specific legal issues rather than the general points of law common to other secondary sources and usually contain case citations and references to other primary and secondary sources. The American Law Reports (ALR) published by Thomson/West is the most comprehensive set of law reports at the present time.
Additional secondary sources include legal treatises which provide very detailed explanations of particular areas of law; legal directories which enable a researcher to locate other legal information such as particular regulatory agencies, attorneys, professors, or other legal experts; loose-leaf services which provide up-to-the-minute coverage on rapidly-evolving and changing laws and statutes; and legal restatements which, as their name would indicate, restate some aspect of a law which may serve to further understanding by a researcher or provide guidance to subsequent court decisions on particular areas of the law.