Understanding Legal Research

The purpose of legal research is to find legal documents that will aid in finding a solution to a legal problem. One type of legal document which many courts will rely on when solving a problem is called “Primary Authority.”

Primary authorities are the laws that are binding upon the courts, government, and individuals. Examples are statutes, regulations, court rules, and case law. They are generated by legislatures, administrative agencies, and courts. 

Secondary authorities are summaries and explanations of the law that do not have binding effect on the courts. Secondary authorities, however, are useful in explaining the law and pointing you towards primary authorities.

Primary Authority


Statutes are laws made by legislatures.  Most legislatures meet and make new statutes at least once a year.

  • The federal government’s legislature is the United States Congress.
  • Each state has its own legislature, such as the Maryland General Assembly.
  • Many cities and counties also have "legislatures."  In Maryland, these local legislatures are called city and county councils. The laws they create are called resolutions and ordinances.

Legislatures have the power to make laws because the state and federal constitutions give it to them, and because the citizens elect them to do so.

Statutes are published in subject arrangements. "Codes" are books where statutes on similar subjects are grouped together.

Some statutory codes, like the Annotated Code of Maryland, are "annotated." The word "annotated" refers to the fact that these codes include more than just the language of the actual statutes - they also provide features such as citations to and summaries of cases and journal articles that interpret the statutes. These extra features are written by the editors of the companies that publish the codes, not by the legislature.


Regulations are laws made by executive branch agencies. Examples of executive branch agencies include the Maryland Social Services Administration and the United States Social Security Administration.  Executive branch agencies have the authority to make laws based on certain statutes passed by the legislatures. Agencies can only make regulations on the subjects that the statutes say they can. You have to read agency regulations together with the statutes they were made under. Regulations, like statutes, are published in subject arrangements called codes.

Maryland’s code of administrative regulations is called the Code of Maryland Regulations (“COMAR” for short), while the federal code of administrative regulations is called the Code of Federal Regulations ("CFR” for short).

Policy Material

Policy materials aren’t laws but they may influence how laws are applied or they may help you to understand the laws. Policy material includes things such as internal agency operating manuals and written opinions that agencies issue to explain decisions they’ve made. For example, an internal operating manual might be issued to the workers in a local Social Security or Environmental Protection Agency field office. An operating manual would contain lists of operating procedures that tell agency workers how to go about making the legal decisions they have to make every day, such as whether an applicant is entitled to disability benefits or whether a factory has met the requirements to receive an emissions permit. An agency’s written opinions explain why they denied the disability benefits or the emissions permit.

Policy materials are sometimes available on an agency’s website. Look on the Peoples Law Library website first for the several user guides on state and federal policy materials. These user guides are usually not written for the general public so you may have to write or call the agency in order to obtain copies of them. You can also check your local public law library for additional help.

Case Law

Case law is found in judges’ opinions, which are explanations for why the judges decided the case the way they did. These opinions are written by the judges after hearing a case. Case law is usually made by judges in the appellate courts rather than the trial courts. Examples of trial level courts include the Maryland District and Circuit Courts, while examples of appellate courts include the Maryland Court of Appeals and the United States Supreme Court.

In making case law, judges apply relevant statutes, regulations, and prior case law to the factual situations brought to them by people who file and defend trial court cases. Applying statutes and regulations usually requires “interpreting” them, or deciding what they mean if their language is confusing (which it often is). Sometimes, the judges are required to interpret the law in a unique way and can seem like the judges are making up new law.

Case law is published in books called “reporters.” There are many different case law reporters in the United States; each different reporter publishes cases from a limited geographical area or government unit. For example, Maryland Reports publishes cases from the Maryland Court of Appeals and Maryland Appellate Reports the Maryland Court of Special Appeals.

Court Rules

Court rules are rules that lay out the procedures that must be followed when conducting business with the courts. For example, court rules explain what must be done when you are serving a legal complaint on a person you want to sue. The court rules also set deadlines and procedures for responding to legal complaints filed against you, limit the kinds of evidence a court may consider, and regulate the process of selecting a jury.

Secondary Authority

Secondary authority are books and articles that attempt to explain or comment on the law. They are not law themselves, because they are not issued by law-making bodies in their official capacities. Most secondary sources are written by law professors or practicing attorneys. These secondary sources are written to help law professors, practicing attorneys and the general public. The articles on the Peoples Law Library are secondary sources which are written to help explain the law to the general public.

Courts are under no obligation to agree with or "follow" an interpretation of the law that appears in a secondary source. Secondary sources are very helpful in doing legal research because they are usually easier to look up by subject and read than the laws themselves. Secondary sources will also point you towards laws and other primary resources. They also tend to explain how several different types of law on a subject (for example, statutes, cases, and regulations) fit together. When possible, it is a good idea to begin legal research with secondary sources, then read and use the primary sources (statutes, cases, regulations, and court rules) they cite.

Is this legal advice?

This site offers legal information, not legal advice.  We make every effort to ensure the accuracy of the information and to clearly explain your options.  However we do not provide legal advice - the application of the law to your individual circumstances. For legal advice, you should consult an attorney.  The Maryland Thurgood Marshall State Law Library, a court-related agency of the Maryland Judiciary, sponsors this site.  In the absence of file-specific attribution or copyright, the Maryland Thurgood Marshall State Law Library may hold the copyright to parts of this website. You are free to copy the information for your own use or for other non-commercial purposes with the following language “Source: Maryland's People’s Law Library – www.peoples-law.org. © Maryland Thurgood Marshall State Law Library, 2020.”