FOUNDATIONS OF LEGAL CITATION INDEXING

The story of using citations in legal research begins with a lawyer’s worst nightmare: looking like a fool in court. In 1807, Maine lawyer Simon Greenleaf based an argument on an English decision that had, unbeknownst to him, been overturned. We cannot judge Greenleaf too harshly for this mistake. Legal research in the nineteenth century was daunting due to the lack of published American caselaw. This unfortunate experience led Greenleaf to study “as far as he could, which of the apparently authoritative cases in the Reports had lost their force, and to give the information to the profession.”¹ Greenleaf developed a lifelong friendship with Supreme Court Justice Joseph Story, who wrote that Greenleaf’s work was “eminently useful, because it accustoms lawyers to reason upon principle, and to pass beyond the narrow boundary of authority.”²

From 1821 to 1856, Greenleaf’s Overruled Cases presented an alphabetical list of American and English cases that were overturned in American courts. It faced criticism for missing cases, but a perfect index with such a massive scope was unattainable at the time. State indexes, which were easier to maintain, developed throughout the mid-nineteenth century. By the 1870s, enough American reporters had been published to create a comprehensive pool of state and federal caselaw. A new wave of lawyers and legal scholars like Melville Below, George Wendling, and Robert Desty published indexes and digests. Frank Shepard also published an index, but Shepard was neither a lawyer nor a legal scholar.

SHEPARD’S CITATION SERVICE

Frank Shepard (1848-1900) was a lawbook salesman who worked for the company that published Wendling’s index. The publication date of Shepard’s first index, Illinois Citations, is up to debate. The year given by Lexis is 1873,³ but some scholars claim it wasn’t until 1875 — the year the Frank Shepard Company opened.⁴⁵ Shepard’s legal citation index consisted of stamp-sized annotations printed on perforated sheets of gummed paper that were placed in the margins of case reporters. Its methodology was simple: Upon publication of a new case, citations were analyzed for change in precedent, and annotations were written. While many indexes were published only once and quickly went out of date, Shepard moved ahead of his competitors by implementing a subscription model for updates.

Shepard’s company went through name changes, acquisitions, and technological advancements throughout the twentieth century, including contracting with West and Lexis simultaneously. In 1999, Lexis introduced a citator product named New Shepard’s that eventually became the beloved Shepard’s Citation Service, where we now enjoy online access to ever-updating color-coded icons that demonstrate the nuance of dicta. The goal remains the same: to stay on top of good law.

EUGENE GARFIELD: THE GRANDFATHER OF GOOGLE⁶

Dr. Eugene Garfield (1925-2017) earned a Bachelor’s in Chemistry (1949) and Master’s in Library Science (1954) from Columbia University. He completed a PhD in Structural Linguistics from the University of Pennsylvania in 1961.⁷ In 1955, he developed a new method for indexing science scholarship using the “journal impact factor.”⁸ The “impact” assigned to each article was based on two elements: “the numerator, which is the number of citations in the current year to items published in the previous two years, and the denominator, which is the number of substantive articles and reviews published in the same two years.”⁹ This research came to life in 1964, when Garfield introduced the Science Citation Index, a tool for researchers “to follow citation links to find the specialized research most germane to their work.”¹⁰ Garfield continued to index scholarship of all disciplines throughout his career.¹¹ Clarivate hosts a database of Garfield’s indexes called Web of Science, described as “documenting the most influential research in any given field as directly judged by researchers themselves, provid[ing] the basis for assessing and benchmarking the research performance of individuals, institutions, nations, and regions.”¹²

Garfield received many letters in response to his indexing projects. One of these was from William Adair, former vice president of Shepard’s, who encouraged Garfield to familiarize himself with Shepard’s methodology. Intrigued, Garfield went to his local library and “screamed out ‘Eureka!’” upon discovering Shepard’s.¹³ At the time, he was struggling to construct a method for indexing reviews. Shepard’s shifted Garfield’s perspective on citation indexing: Instead of having the impact factor be the researcher’s focus, the primary document had to be the focus. After all, one of the purposes of citation research is to use a primary resource to find information on other resources.

INDEXING IN THE INFORMATION AGE

Coders in the 1990s were also inspired by the work of Garfield and his contemporaries. A new perspective was required, once again. In comparison to caselaw or journal articles, websites “frequently do not acknowledge one another’s existence.”¹⁴ Research on the World Wide Web required analysis of text. Early search engines used basic metrics — for example, the frequency of a keyword. As the number of websites grew and coding became more complex, it was clear that an even more advanced algorithm was required to organize the online world.

IBM’s CLEVER Project (1996) analyzed website text with an algorithm that categorized websites as either “hubs” or “authorities.”¹⁵ This algorithm is similar to Garfield’s journal impact factor: Some websites are standalone authorities, while others are a hub of other websites. “Authorities” have a higher impact and therefore should be higher on a search result list than a “hub.” Google’s founders were also inspired by Garfield and his contemporaries. When Google discovers new websites, its algorithm tool, PageRank, identifies and indexes text using a variety of metrics.¹⁶ When we conduct a search on Google, we are not searching the World Wide Web. Rather, we are searching Google’s index of websites.

FINAL THOUGHTS

The evolution of citation indexing reflects the ever-present need for accurate and organized authoritative information. From sticking annotations in a reporter margin to digital indexing of websites, each step in the development of indexing has been driven by the goal to ensure the most relevant, reliable sources rise to the top.