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Summer Associate Research Guide: Research Caselaw Using Digests

This guide is intended for students who will be working at law firms over the summer. It is similar and related to the Experiential Learning Resources Guide which focuses more on externships and clerkships.


As a summer associate or intern you may be asked to do caselaw research in print. This technique is not one we covered in First Year Legal Research. The purpose of this page is to provide you with the background and resources to enable you to succeed in this endeavor.

Instructional Videos

Below are detailed written instructions of how to use the Digest System (interchangeably known as West's Topic and Keynumber System in print) to locate relevant caselaw. The essence of these instructions, as they apply to using the Illinois Digest 2d are contained in the following three instructional videos

Step 1: Determine Your Starting Point

  •  If you have specific information about a particular case:
    • If you have only the party names – See the Tables of Cases located at the end of each Digest (See Step 2 to determine in which Digest in to look). Shepard’s Acts and Cases by Popular Name, Federal and State, is another index by popular name.
  • If you do not have specific information about a particular case, but rather have a “research subject” consisting of a legal issue or fact pattern, or combination of the two, proceed to Steps 2 and 3, below, to find cases relevant to your research subject.
    • Keep in mind that Reporters are nothing more than chronological, jurisdiction-by- jurisdiction compilations of cases in their area of coverage (by jurisdiction or in some instances, by subject, such as bankruptcy). So to access the cases in the Reporters, you will need resources other than the Reporters themselves. That is where Digests come in. Digests reprint the Headnotes of every case published in the Reporters, arranged by subject. Essentially, they constitute a massive subject matter index to the system of Reporters.

Step 2: Choose the Proper Digest

The next step is choosing the proper Digest for the jurisdiction(s) in which you are researching. Because a key criterion of a case’s relevance is whether it comes from a controlling authority (e.g., Wisconsin Supreme Court cases will be of diminished precedential value in an Illinois court), it is important to be sure you are searching in the proper place. The following Digests will be most relevant to  your research questions in Illinois:

Digest Name

Illinois Digest – 1818-1938, Illinois Digest 2d – 1938 –

Reporters (Courts) Covered

Federal Court Reporters*
United States Reports, Supreme Court Reporter, Federal Reporter,
Federal Supplement, Federal Rules Decisions, Bankruptcy Reporter        
*N.b., only Illinois federal case decisions are included in the Illinois Digests

Illinois Court Reporters
Illinois Digest – 1818-1938 Illinois Digest 2d – 1938 –
Illinois Reports (Illinois Supreme Court) Illinois Appellate Court Reports (Illinois
Appellate Courts)
Illinois Decisions (Illinois Supreme Court and Appellate Courts)
North Eastern Reporter (All Illinois Courts)

Step 3: Find Relevant Cases Using Topic and Keynumber System

After you have chosen the proper Digest, analyze the factual and legal issues involved in order to define the subject of your research so that you can find it in the Digest. Digests arrange the headnotes of the Reporter(s) into topics.  They cover approximately 400 alphabetically arranged subject headings known as “Topics” and numerically ordered subdivisions of each Topic known as “Key Numbers.” Once you are clear on what you are looking for, there are three good strategies for finding relevant Topics and Key Numbers:

  • Use the Descriptive Word Index at the end of each Digest set.  You can look up either legal issues (causes of action, defenses, type of relief sought), or factual elements (persons, places or things involved). Be forewarned – while the Digest indexes are thorough, this can be a frustrating exercise. It will be helpful, as you go along, to pause to rethink issues, reframe questions, check synonyms and alternate terms (thesauri or a legal dictionary may help), and to follow up on cross-references. Once you have found a Topic and Key Number that looks good, turn to the appropriate Digest volume to begin finding Headnotes identifying relevant cases. Before you actually get into the cases, take just a minute to check the outline at the beginning of the Topic to make sure you are in the right legal context. You do not want to end up in a discussion of procedural issues (burden of proof, for example) if you are looking for the substantive elements of a particular cause of action.
  • Go directly to the Topic Index to find the Topic and Key Numbers most relevant to your search. There is a list of Topics and a Table of Contents in the front of every Digest volume. Looking through them can be helpful in clarifying issues or raising concerns you had not thought of. But handle this approach with care – it can be time consuming and confusing, especially if you do not already have a basic background in a given legal area.  This method is probably best used in conjunction with a Descriptive Word Index search, or in an area you know well.
  • Use the Key Numbers from Headnotes from a relevant case you already have. Once you have one good case on point, you can “leverage” it by looking in its headnotes for the relevant issues. Then take the Key Numbers from the headnotes and look in the appropriate Digest for additional cases. This is the easiest and most direct way to use the Digests. The trick, obviously, is to find that first relevant case. Try starting out with one of the first two methods discussed above, or use the resources discussed in the Handout “Finding Background Information on Legal Topics,” to find that first relevant case. Remember – Key Numbers are the same in all jurisdictions, so even a case from another, noncontrolling jurisdiction can be helpful in finding a good Headnote to pursue in this way.

Subject Guide