Legal Research Tools: Challenging Westlaw and LexisNexis Dominance

Lexis and Westlaw have been best in class in legal research. As of today, that is no longer true. Your skepticism is welcome. Lawyers are paid to be right. But they are expected to not be wrong. You are justifiably hesitant to experiment. But you should experiment. Your competitors already are. I am not arguing that you should leave Westlaw or Lexis. Yet. But if you review the evidence and access our tool (which we are giving away until the end of October), I am confident you will be convinced, not only that these other platforms might not be necessary, but that they are no longer state of the art. Let’s start off with some background. For decades, two companies have controlled public case law and legal research. They have succeeded largely in two ways: First, both companies have manufactured a quasi-governmental hold over case law. Thankfully, these unprincipled bureaucratic protections prove no match for our agentic world. American case law, our national legal heritage, yearns to be free. So we freed it. With LOIS, Filevine has built a formidable corpus of American case law from every state and every federal court from the country’s founding to today. The corpus is updated daily and, beginning later this month, will include reporter pagination and citations for published opinions. Filevine assembled this collection from a wide range of public and licensed legal sources, including resources made available by community-minded organizations like CourtListener. Other materials come from established legal-data providers whose research is used by some of the world’s largest companies. To our research partners and others involved in this effort to broaden access to legal information, our gratitude runs deep. Second, Westlaw and Lexis have, historically, had the only credible citators in the industry. Practicing law requires more than a strong corpus. It requires lawyers to cite cases and holdings that are still “good law.” West’s KeyCite and Lexis’ Shepardization, also called “Shepard’s,” have been institutionalized as authoritative. Yet these tools carry a hidden cost. They force lawyers to adapt their research to the limitations of the software. A lawyer cannot simply describe a legal issue and ask for the best authority. They must learn specialized search syntax, anticipate the database’s taxonomy, and manually interpret a maze of signals and citing references. Even experienced lawyers struggle to use them reliably. They call vendor help desks, delegate searches to less expensive associates, and spend hours validating authorities. The legal industry has come to treat this complexity as an inherent part of legal reasoning. It is not. KeyCite and Shepard’s are beset by serious structural deficits we will detail below. Both citators are remarkably brittle, and the authorities they return often have little overlap. The gaps in citator results aren’t widely known but should be shocking to any practitioner. As John Rizner (J.D., University of Chicago, 2018), who heads our citation project, observed, reiterating Paul Hellyer’s findings below: “A lawyer’s citation accuracy has more to do with which product they subscribe to than the case law being evaluated.” Filevine is not the first to point out the problems inherent to legacy citators. Susan Nevelow Mart, Professor Emeritus at University of Colorado Law School and former director of the William A. Wise Law Library, has written extensively on the topic, including The Relevance of Results Generated by Human Indexing and Computer Algorithms: A Study of West’s Headnotes and Key Numbers and LexisNexis’s Headnotes and Topics , 102 Law Libr. J. 221 (2010) and her follow-up The Case for Curation: The Relevance of Digest and Citator Results in Westlaw and Lexis , 32 Legal Reference Services Q. 13 (2013). In The Case for Curation , Professor Mart and her team compiled a set of 90 c