Digests, Headnotes, and Key Numbers Research Guide
This guide explains how to use West Digests, Headnotes, and Key Numbers to find case law.
A digest's major function is to allow you to find cases on a specific legal issue or topic. West digests use headnotes and key numbers to organize and summarize all cases by subject. Digests are available in print in the library. In addition, Westlaw provides searching by topic and key number, thus allowing you to create your own "custom digest" online.
What is a Headnote
Before a case is published in a reporter, an editor at West reads the case and selects the important issues of law. For each major issue, the editor then writes a short description called a headnote. These headnotes are typically found at the beginning of each opinion and help the reader to determine quickly the issue(s) discussed in the case. For example, here is the third headnote of a U.S. Supreme Court opinion, Gideon v.Wainwright, 372 U.S. 335:
3. Constitutional Law
Sixth Amendment to federal Constitution providing that in all criminal prosecutions the accused shall enjoy right to assistance of counsel for his defense is made obligatory on the states by the Fourteenth Amendment, and indigent defendant in criminal prosecution in state court has right to have counsel appointed for him. Betts v. Brady, 316 U.S. 455, 62 S.Ct 1252, overruled. U.S.C.A.Const. Amends, 6, 14.
The headnote describes one major issue in the case: whether an indigent defendant in a criminal prosecution in state court has the right to have counsel appointed for him. The broad topic assigned is Constitutional Law, and the number assigned to that topic is 92. The key number is 4809.
What is a Key Number?
When writing the headnotes, the West editor gives each one a "headline" (broad topic) selected from a list of about 450 possibilities. Some examples are "Landlord and Tenant," "Intoxicating Liquors," or "Automobiles." Finally, the editor will assign the headnote a specific subtopic, such as "Injury to tenant or occupant." In West digests, this subtopic is represented by a number called a key number. In the example above, within the topic "Constitutional Law," the key number for "Appointment of Counsel" is 4809. Each topic and key number combination represents a unique point of law. Key numbers are the same in all West digests for all jurisdictions; therefore, to find Massachusetts cases on the same topic as the Supreme Court case above, you would use the same topic and key number, Constitutional Law 4809.
Using a Digest
Step One: Finding a Key Number
Before you use a digest, it's best to already have one or more key numbers of interest. There are many ways to identify useful key numbers. If you already have a good case on your topic, simply find the case in a West reporter or on Westlaw and look at the headnotes to find the appropriate key number(s).
If you don't already have a good case, there are numerous methods of finding one. Encyclopedias, ALRs, law reviews, annotated codes, treatises, hornbooks, keyword searches, professors, law librarians, and other experts can be helpful sources for finding a leading case on a topic. Once you have found a case, look at the case in a West reporter or on Westlaw to find the relevant key number(s). Now you're ready for step two.
Another method is to use the Descriptive-Word Index (usually the last few volumes of the digest set) to locate a key number. Many researchers find the digest's index difficult to use because the terms used in the index may not be the terms you would use to describe your issue. Most indices have cross-references to lead you to the right index terms for your topic. You might have to search synonyms to find the appropriate index term.
Step Two: Selecting the Appropriate Digest
The second step is usually straightforward: choose the best digest for your needs. The following lists major digests and the jurisdictions or reporters they cover. Digests are located near their reporter. Check GULLiver for call numbers.
|Supreme Court Digest|
|United States Supreme Court Digest||Supreme Court, 1790-present|
|Federal Court Digests|
|Federal Digest (red)||Federal (Supreme Court Reporter, Federal Reporter, Federal Supplement), pre-1939|
|Modern Federal Practice Digest (green)||As above: 1940-1960|
|Federal Practice Digest 2d (blue)||As above: 1961-Nov. 1975|
|Federal Practice Digest 3d (red)||As above: Dec. 1975-1987 (some volumes close as early as 1983)|
|Federal Practice Digest 4th (blue)
||As above: 1983-present (some volumes begin as late as 1987 and close as early as 2003)
|Federal Practice Digest 5th (red)||As above: 2003-present (started in 2013 but will take 5 years for all volumes to be released and the 4th series to be closed)|
|The only regional digest the library maintains a print subscription to is the Atlantic Digest.|
|Atlantic Digest||1st and 2d series, see volumes for dates: CT, DC, DE, ME, MD, NH, NJ, PA, RI, VT|
|North Eastern Digest||No longer published, see volumes for dates: IL, IN, MA, NY, OH|
|North Western Digest||1st and 2d series, see volumes for dates: IA, MI, MN, NE, MD, SD, WI||Library no longer maintains a print subscription|
|Pacific Digest||Four series, see volumes for dates: AK, AZ, CA, CO, HI, ID, KS, MT, NV, NM, OK, OR, UT, WA, WY||Library no longer maintains a print subscription|
|South Eastern Digest||1st and 2d series, see volumes for dates: GA, NC, SC, VA, WV||Library no longer maintains a print subscription|
|Southern Digest||No longer published, see volumes for dates: AL, FL, LA, MS|
|For states and time periods not covered by regional digests, use state digests. State digests are available for each state except Delaware, Nevada, and Utah. There is also a District of Columbia digest. The library maintains a print subscription to the digest for the District of Columbia, Maryland, and Virginia / West Virginia.|
|West's District of Columbia Digest||1st and 2d series|
|West's Maryland Digest||1st and 2d series|
|Virginia and West Virginia Digest|
|West's New York Digest||1st - 4th series|
|West's California Digest||1st and 2d series|
|American Digest (also known as the Decennial Digest)||1658-present (Century Edition, First Decennial - Eleventh Decennial)||Library no longer subscribes to the General Digest which updates the Decennial Digest|
In addition to the printed digests, you can search by topic and key number on Westlaw. You can search for a topic and key number by clicking "Key Numbers" on the All Content tab on Westlaw's homepage.
Step Three: Reading Headnotes and Cases
Step three is simply to 1) find your digest, select the volume containing your topic, find your key number, and read the headnotes listed to find useful cases or 2) retrieve headnotes with your key numbers on Westlaw. It is important never to cite a case directly from the digest because the headnote contains only limited information about the case. Instead, note the citations of interest. Then use the citations to find and read the opinions in full. Print digests are updated by pocket parts and paper supplements, so don't forget to check those for the newest cases.
- If you are researching many years of cases, you may have to use more than one digest or search more than one database on Westlaw to cover the desired time period. Older cases may be just as important as newer cases for some legal issues.
- A useful feature of a digest is the lists of cases by name in tables found at the end of the digest. Using these name tables, you can find a case for which you have a name, but no citation. Similarly, Westlaw and Lexis have features that allow you to search for a case by the names of the parties.
- A few digests are published by other companies than West. For example, there is a digest to accompany the Lawyers Edition Supreme Court reporter, which is published by Lexis. A few states also have digests produced by other publishers. Some looseleaf services contain their own digests to cases on particular subjects. Although each of these companies has a unique classification system each with its own set of topics and subtopics, the basic system is similar to a West digest: find the appropriate topic and subtopic and look under that combination to find descriptions of and citations to cases on point. Once you are comfortable using one digest system, you will find it easy to use others.
- Our Case Law Research Tutorials have additional information about headnotes, key numbers, and digests.
- Don't hesitate to consult a reference librarian for further assistance:
- by email: firstname.lastname@example.org
- by phone: 202-662-9140
- at the Reference Desk (Mon-Fri: 9:00 a.m. - 8:00 p.m.; Sat and Sun: noon - 6:00 p.m.) during the academic year.
Updated 9/14 (CPW)
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