How do I Find the Appropriate Topic and Key Numbers?
Does this mean that if you want to do good legal research that you're going to have to memorize approximately 100,000 Key Numbers?

No way!! That is the great thing about the way the Key Number System® has been put together. You don't really have to memorize anything. You just start with an idea and follow a logical thread of information until you find what you need. The Key Number System's organization does all the real work for you. All you need to do is become familiar with the concept of Key Numbers and how they work.

Seven Methods for finding the Appropriate Topic and Key Number(s)

Topic Method
Finding the right topic can be the first step to find the right Key Number, especially if using print research products.
  1. In the print Digest, there is a topic list at the beginning of each volume and a Subjects Included and Subjects Excluded and Covered by Other Topics section at the beginning of each topic. Peruse the topics, reading the scope notes at the head of each topic -- and even read the lines themselves.
  2. On, click the More pull-down list in the right corner of the toolbar, select Key Numbers & Digest and an expandable-collapsible Key Number outline will be displayed. Click here for the West Key Number System on
Descriptive Word Method
Select specific words that describe the problem or concept. Then, use a Descriptive Word Index (DWI) volume to search for references to those words, which will then lead you to the proper Topics and Key Numbers.

West's Analysis of American Law
This print product is arranged first alphabetically by Topic and then numerically by Key Number. Each Key Number is titled so you can zero in on the Key Numbers that are most relevant. Find "your" Key Numbers -- and be well on your way to thorough case law research. Use it to find West cases in print or online.
   Start by looking at these features:
  • Topic list
  • Topics by Specialty Table
  • Outline of the Law
    To find more detailed information, check out these features:
  • Topic Notes
  • Cross-References
  • Key Number Outline
Library References in Print and Online
ALRs, Am Jur 2d, CJS, Forms, practitioner guides and annotated statutes, and many other legal materials will contain references to relevant Topic and Key Numbers.

Known Case Method
  1. In print, read the headnotes for the known case to find the headnote(s) and assigned Key Number(s) that are relevant to your issue. Use a West Digest to find all the headnotes that are assigned to these Key Numbers in your jurisdiction.
  2. To create a Custom Digest online, click the Most Cited Case link following a relevant Key Number in the case. You can create a Custom Digest of headnotes assigned to that Key Number in the selected jurisdiction.
Retrieved in a Case Law Search on Westlaw Method
Conduct a Terms & Connectors or Natural Language search on Westlaw. Use the Terms or Best arrows to browse the cases, carefully checking the headnotes and Key Number hierarchy that might contain your terms.

A very focused search is a Terms & Connectors Field search in the Digest field. (The Digest field contains the headnotes and Key Numbers.) An example of a Digest field search is: di("social host" /p liab! /p injur! harm! /p intoxicat! drunk! /s guest). Any case retrieved with this search would ensure that the issue is central to the cases retrieved and very relevant Key Numbers would be assigned to those headnotes.

ResultsPlus on Method
When you run a word search in a case or statute database, as a bonus, you will retrieve links to relevant secondary source materials, including Topic and Key Numbers.