Are there any empirical studies showing that the quality of the writing in a brief has an effect on its success?

In general, the answer is no. But new research is happening, and I’d like to highlight two important articles on the subject.

The first article reports on a study of the use of intensifiers (very, clearly, obviously, and the like) in appellate briefs. The authors state, correctly, that lots of experts on legal writing recommend against intensifiers and especially against their overuse. The authors then measure intensifier use against outcomes. Their conclusion:

• Using intensifiers frequently in a brief, particularly a brief for the appellant, is usually associated with a statistically significant increase in adverse outcomes for the party using the intensifiers.

Lance N. Long and William F. Christensen, Clearly, Using Intensifiers Is Very Bad—Or Is It? 45 Idaho L. Rev. 171, 171 (2008).

When appellants use a lot of intensifiers, they tend to lose.

The authors clarify that no causal connection is shown, but the article is still interesting and useful.

The second article, by the same authors, reports on a study of the readability of briefs. The authors measured briefs according to the Flesch Reading Ease scale—a scale of zero to 100 that measures average word length and average sentence length, with “plain English” being a score of at least 60. (The briefs in the study tended to average about 33-34 on the scale.)

The authors measured readability scores against outcomes. Their finding:

• Using the Flesch Reading Ease scale, the authors found no statistically significant relationship between the readability of a brief and its success.

Lance N. Long and William F. Christensen, Does the Readability of Your Brief Affect Your Chance of Winning an Appeal?—An Analysis of Readability in Appellate Briefs and Its Correlation with Success on Appeal, 12 J. App. Prac. & Proc. __ (2011).

Shorter sentences and smaller words won’t necessarily win.