The United States Supreme Court is a singular institution within the American judiciary. It has many unique institutional features, such as the ability to select the cases that it will decide, and it plays a unique role in American political and social life. However, while as an institution the Supreme Court is distinctive, it remains recognizably a court of law. The Supreme Court shares certain rituals with other US judicial institutions, such as the black robe and gavel. It also shares many procedures with other courts, including adversarial hearings and restrictions on ex-parte contacts. Perhaps most important is that its mode of decision-making is through case-by-case adjudication, typically in the course of hearing an appeal from a lower court decision. As such, when the court creates, amends, or clarifies legal obligations, it does so not through directly stated rules (as in a statute or regulation) but through the justificatory documents that accompany a disposition in a particular case, largely embodied in the written opinions of the court and its justices. The judicial opinions of the US Supreme Court serve as among the most important pieces of “data” in understanding the evolution of legal thought and sociopolitical dynamics in the United States. The judicial opinions issued by the Supreme Court have provided legal scholars (and others) with fodder for analysis since the dawn of the American legal academy. Recent advances in natural language processing and computational text analysis provide new ways to examine and understand the work of the court. In this chapter, we will discuss our research using these kinds of tools on two sets of questions concerning the court that are particularly well suited to such analysis. First, we examine trends in writing style on the court through sentiment analysis and a form of stylometry based on the frequency of function words in a text. Second, we examine whether the Supreme Court has begun to carve out a unique judicial genre by examining how the content of Supreme Court opinions differs from the federal appellate courts that it supervises.

Jon Ashley et al., Style and Substance on the US Supreme Court, in Law as Data: Computation, Text, & the Future of Legal Analysis, Santa Fe Institute Press, 83–115 (2019).