BY LAUREN STONE, Law Student, University of Baltimore

Suppose you are providing a friend with directions to your home or office. This is a route you take every day, and you know it well. You quickly describe what roads to take as your prospective visitor takes notes. But in your familiarity with your own route and haste in providing the instructions, you inadvertently gloss over some of the turns. Your visitor misses a crucial exit. Without making the exit, the visitor misses some of the steps and continues coasting down the highway and never arrives at the final destination.

Accurate and complete driving directions are essential for drivers to arrive from one point to another. A missing step makes the entire set of directions confusing and may prevent the driver from arriving at their destination. In legal writing, writers likewise want to guide their readers through the caselaw to forge connections and reach the intended destination. If steps in the directions to reach the conclusion are missing, the analysis will be incomplete, and the reader has a reduced chance of agreeing with the desired conclusion.

Legal analyses require logical arguments with each step of the reasoning laid out in a manner so readers can follow the argument, evaluate its soundness, and decide if it is persuasive.1 To avoid conclusory reasoning, legal writers must “show their work” and avoid analytical gaps in their reasoning. Clear and logical reasoning, in which authors show their work, is a hallmark of a persuasive analysis. However, sometimes an otherwise detailed legal analysis is missing a step and skips a crucial link in the reasoning. There is a leap between the premise and its application.

The concept of an analytical gap was crystallized in General Elec. Co. v. Joiner, a follow-up case to Daubert v. Merrell Dow Pharmaceuticals, Inc., which provided a standard for measuring expert reliability.2 Daubert was a medical products liability case involving assertions that a particular cluster of birth defects was linked to a morning sickness pill; this assertion needed expert testimony to provide a supporting link.3 Daubert provided a multi-factor test to help judges determine whether an expert’s opinion testimony was reliable enough

to be admitted.4 Joiner extended those factors, particularly where the expert’s opinion has made a leap in reasoning not supported by evidence.5 The plaintiff in Joiner was an electrician who alleged that his lung cancer had been “promoted” by exposure to certain chemicals at his employment.6 Some of these chemicals had been linked to prostate cancer in mice, and the plaintiff ’s expert argued that this supported the conclusion the plaintiff ’s lung cancer was linked to the same chemicals.7 The trial court declined to accept that inference, and the U.S. Supreme Court in Joiner held that reliability of expert opinion was traceable to the expert’s methodology and the extent to which it linked the opinion with data.8 If the analytical gap between the data and the opinion is too great, a court need not—and likely will not—accept the opinion.

Expert reports are different from legal writing because the first is evidence and the second is an argument meant to inform or persuade. However, Joiner can be helpful to understanding why analytical gaps lead to less persuasive analyses.

But why do writers skip steps in their legal reasoning that are necessary to make their points persuasively? In legal writing, the gap is sometimes created because the author is moving too fast. They have already reached the end of the reasoning chain by the time the words have been typed on the screen.

The author is familiar enough with their own thoughts that when they re-read what they have written, their brain automatically fills in the gap for them, and they don’t even notice that a gap is present. This problem persists even in projects with more than one author if they are not proofreading carefully or if they have worked with each other enough that they automatically fill the inferential gap themselves.

When the gap is identified, writers can often explain the link in their reasoning and fill the gap. This forces them to go back and show the work behind their reasoning, which allows the reader to understand the reasoning too. Alternatively, when faced with the gap, writers sometimes realize there is a flaw in their reasoning and they have to rework their argument. In both cases, redevelopment is necessary because the reader cannot provide the inferential link that exists in the author’s mind. Either outcome results in a stronger and more fully developed analysis that reduces inferential leaps, which should lead to the argument being more persuasive.

Fortunately, there are safeguards writers can use to ensure a legal argument does not suffer from an analytical gap. The first involves planning sufficient time to detach from the work and returning with a fresh mind to slowly and intentionally proofread.9 This can allow the writer to objectively review their reasoning and identify the analytical leaps on their own. The second is to have a colleague proofread the analysis.10

In addition to double checking the quality of the work, peer review can also test whether a neutral person can follow the writer’s analysis without making mental leaps. The third is to plan enough time to rewrite the draft.11 Rewriting already forces the author to reword and reorganize their draft. By rearranging the analytical steps, the author can more easily see and thus reduce the possibility of an inferential leap.

Properly avoiding analytical gaps in legal writing is crucial for persuasive arguments. Like any other skill, it requires practice and time, but strong legal analysis is worth it.

  1. Nicholas Lucas, Logic and Law, 3 Marq. L. Rev. 203 (1919); see also Douglas Lind, The Significance of Logic for Law, Nat’l Judicial College (Oct. 4, 2014),
  2. General Co. v. Joiner, 522 U.S. 136, 146 (1997) (relying on Daubert v. Merrill Pharms., Inc., 509 U.S. 579 (1993) to hold that an expert’s mere use of an acceptable methodology does not require a court to admit the opinion if the expert’s conclusions are not properly linked to the data).
  3. Daubert, 509 S. at 582.
  4. Id. at 593, 594 (describing a “flexible standard” comprising a non-exhaustive list to include whether a theory or technique has been tested; whether it has been peer reviewed; the error rate; and general acceptance in the relevant community).
  5. Joiner, 522 U.S. at 146
  6. Id. at 140.
  7. Id.
  8. Joiner, 522 U.S. at
  9. See June Casagrande, A Word, Please: Here Is What Happens to the Brain When Editing Your Own Work, LA Times, (Dec. 4, 2015, 3:31 PM), socal/daily-pilot/opinion/tn-hbi-et-1224-casagrande-20151224-story.html.
  10. See Susan Provenzano and Lesley Kagan, Teaching in Reverse: A Positive Approach to Analytical Errors in 1L Writing, 39 U. Chi. L.J. 123, 174(2007) (suggesting use of collaborative, social techniques as a method to eliminate analytical gaps in legal writing).
  11. Danielle Pineres, Ten Tips for Transitioning to Legal Writing, U. L. Ctr., Legal-Writing-Final.pdf (last updated in 2017 by Michael Fazio).