Research on Persuasive Legal Writing

Three recent projects

My books: Legal Writing Nerd and Plain Legal Writing

When I first learned about persuasive legal writing, the advice was simple: avoid lying, follow the rules, reduce errors. Today, we have science, and many authors are publishing research studies that try to define persuasive legal writing scientifically. I summarize three here.

Brady Coleman and Quy Phung assembled a database of U.S. Supreme Court briefs filed from 1970 to 2004 and performed some calculations: they used the Flesch Reading Ease Scale, which assigns a readability score from zero (extremely difficult) to 100 (very easy); they also used the Flesch-Kincaid Grade Level, which assigns a number representing the years of education the reader would need to read the text comfortably (12 = high school graduate, 16 = college, etc.)

Their data show that U.S. Supreme Court briefs are becoming more readable. During the period of their study, they found that—

  • the Argument section’s readability increased from 33 to 39.
  • the Argument section’s grade level moved from 15 to 12.
  • the Statement of Facts’ grade level moved from 14 to 13.[1]

I’m not willing to believe that these briefs became “simpler” because the writers got dumber. Instead, I think lawyers are learning that readable briefs are more persuasive.

In another study, Shaun Spencer and Adam Feldman reviewed 654 summary judgment motions—trial briefs. They scored the briefs with 50 readability measures, assessing word difficulty as well as syllable, letter, and sentence counts, and they produced a readability score for each brief.

After controlling for multiple factors, internal and external to the briefs, the authors found that a brief’s readability was significantly correlated with success at summary judgment. Meaning: the easier your brief is to read, the more likely it is that you’ll win. The correlation was even stronger in federal court than in state court.

Specifically, if the moving party’s brief was significantly less readable than the nonmoving party’s brief, the moving party had only a 42% chance of winning. But if the moving party’s brief was significantly more readable than the nonmoving party’s brief, it had an 85% chance of winning.[2]

I should mention that you can assess the readability and grade level of your own writing. In Microsoft Word, go to File and select Options and then Proofing. Check the box for “Show Readability Statistics.” Now, after a spell-check, you’ll see a display that includes your Reading Ease score and grade level.

Finally, lawyers and legal-writing teachers have long believed that stories are persuasive, and now there’s evidence to prove it. This legal-writing expert, Kenneth Chestek, sent briefs written for a fictional case to 95 judges, clerks, staff attorneys, practitioners, and law professors.

Each reviewer received two briefs. In one brief, the argument had a narrative component—characters who encounter an obstacle and seek to overcome it—plus the legal argument. The other brief advocated for the same party but with only the legal argument; it had no narrative component. The author’s data showed that 64% found the narrative briefs more persuasive.[3] That’s a solid, nearly two-thirds majority in favor of story.

You probably knew this already, but now there’s science: when you need to write persuasively, science tells you to write readably and tell a story.

My books: Legal Writing Nerd and Plain Legal Writing


[1] Brady Coleman & Quy Phung, The Language of Supreme Court Briefs: A Large-Scale Quantitative Investigation, 11 J. App. Prac. & Process 75, 98, 99 (2010).

[2] Shaun B. Spencer & Adam Feldman, Words Count: The Empirical Relationship Between Brief Writing and Summary Judgment Success, 22 J. Leg. Writing Inst. 61, 94 (2018).

[3] Kenneth Chestek, Judging by the Numbers: An Empirical Study of the Power of Story, 7 J. Assn. Legal Writing Directors 1, 19 (Fall 2010).