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Legal Research Strategy

Types of Sources

There are three different types of sources: Primary, Secondary, and Tertiary.  When doing legal research you will be using mostly primary and secondary sources.  We will explore these different types of sources in the sections below.

Graph Showing Types of Legal Research Resources.  Tertiary Sources: Hollis, Law Library Website.  Secondary Sources:  Headnotes & Annotations, American Law Reports, Treatises, Law Reviews & Journals, Dictionaries and Encyclopedias, Restatements.  Primary Sources: Constitutions, Treatises, Statutes, Regulations, Case Decisions, Ordinances, Jury Instructions.

Secondary sources often explain legal principles more thoroughly than a single case or statute. Starting with them can help you save time.

Secondary sources are particularly useful for:

  • Learning the basics of a particular area of law
  • Understanding key terms of art in an area
  • Identifying essential cases and statutes

Consider the following when deciding which type of secondary source is right for you:

  • Scope/Breadth
  • Depth of Treatment
  • Currentness/Reliability

 

Chart Illustrating Depth and Breadth of Secondary Sources by Type.  Legal Dictionaries (Shallow and Broad), Legal Encyclopedias (Shallow and Broad), Restatements (Moderately Deep and Broad), Treatises (Moderately Deep and Moderately Narrow), American Law Reports (Extremely Deep and Extremely Narrow), Law Journal Articles (Extremely Deep and Extremely Narrow)

 

 

Legal Dictionaries & Encyclopedias

Legal Dictionaries

Legal dictionaries are similar to other dictionaries that you have likely used before.

Legal Encyclopedias

Legal encyclopedias contain brief, broad summaries of legal topics, providing introductions and explaining terms of art. They also provide citations to primary law and relevant major law review articles.  

Graph illustrating that Legal Encyclopedias have broad coverage of subject matter and content with shallow treatment of the topics.
Legal encyclopedias cover a broad range of topics superficially.

 

Treatises

Treatises are books on legal topics.  These books are a good place to begin your research.  They provide explanation, analysis, and citations to the most relevant primary sources. Treatises range from single subject overviews to deep treatments of broad subject areas.

Graph illustrating that Treatises are moderate in scope and relatively deep.
Treatises typically cover a single legal subject area deeply.

 

It is important to check the date when the treatise was published. Many are either not updated, or are updated through the release of newer editions.

Law Reviews & Journals

Law reviews are scholarly publications, usually edited by law students in conjunction with faculty members. They contain both lengthy articles and shorter essays by professors and lawyers. They also contain comments, notes, or developments in the law written by law students. Articles often focus on new or emerging areas of law and may offer critical commentary. Some law reviews are dedicated to a particular topic while others are general. Occasionally, law reviews will include issues devoted to proceedings of panels and symposia.

Graph illustrating that Law Review and Journal articles are extremely narrow in scope but exceptionally deep.

Law review and journal articles are extremely narrow and deep with extensive references. 

To find law review articles visit: