A digest allows you to redefine your research goals and theories to find the best precedents for your research problem. Your research is not complete if you haven't considered using digests. A digest is a case finding tool and should not be relied upon to interpret cases. Digest editors can and do make mistakes, and small excerpts from cases are often misleading about the actual statement of law found in a case. Example of a headnote from a West Key Number Digest.
Some digests are separate sets of books.
Others are just sections of larger works, such as those found in looseleaf services. Digests are characterized by the information they digest. Digests may contain headnotes of cases from an individual court, a court system, a group of related courts, or from cases related by subject matter or date of decision. The most extensive publisher of digests, West Group, uses the same topic and key number system for all its digests. At the beginning of each digest topic is a Topic Analysis that explains what each key number within that topic represents.