Skip to Main Content

Law Library

Legal Research Review: WestlawNext

Subject Searching on WestlawNext

The West Key Number System

West has divided all American law into over 400 Topics

Each Topic is represented by a word or phrase and has been assigned a number.  Topics are subdivided into subtopics called Key Numbers.  Key Numbers are sometimes divided into subtopics.

For Example:

Topics and Key Numbers always work together.

Topic is Animals; Topic number is 28
Key Number is a Subtopic. Key Number 66.5 covers cases in which a dog known to be viscious injured a person. (Key Number 2.5 covers licensing of animals). 

Shorthand = 28K66.5


3 Ways to Use Topics & Key Numbers to Find Cases:

  1. Use a Known Topic number & Key number as a Search Term.  E.g., 28K66.5 /p bite
  2. Browse the Topic Outline &
    • Pre-Search filter by Jurisdiction
    • Browse Box >  Tools tab >  West Key Number System
      • Drill down to best Topic and Key Number, OR
      • Search using the "Title Search" box.
    • Search within the results
  3. "One Good Case Method"  (see below)

One Good Case Method

A West headnote is the summary of one legal issue in a case. Cases often have multiple headnotes. Each headnote is assigned a Topic and Key Number.

With an on point case, you can find add'l cases addressing the same issue in the same or different jurisdiction. 

  1. Find a headnote that is on point
  2. Click on the Topic and Key Number link to find cases in the same jurisdiction
  3. Click on the "change" next to Jurisdiction to find cases in different jurisdiction.

Example headnote from Bussell v. Tri-County Humane Society, 50 S.W.3d 303 (Mo. Ct. App. 2001)


Word and Terms & Connectors Searching on WestlawNext

For an introduction to Word and Terms & Connectors searching on WestlawNext, see LRM: Searching Bloomberg Law, Lexis Advance and WestlawNext.


  • When selecting terms to search, be sure to include legal terms. If you know a "term of art" use it.
  • To search within fields, select a WestlawNext database and then click on "Advance" next to the search button.
  • On WestlawNext using connectors does not automatically trigger a Terms & Connectors search. You must use a proximity or grammatic connector in the Search Box; type adv: before your search; or use the Advanced search template.