How Courts Adjudicate Patent Definiteness and Disclosure

87 Pages Posted: 21 Mar 2015 Last revised: 13 Jan 2016

See all articles by John R. Allison

John R. Allison

University of Texas - McCombs School of Business

Lisa Larrimore Ouellette

Stanford Law School

Date Written: March 19, 2015


In exchange for the rights provided by a patent, § 112 of the Patent Act requires patentees to clearly explain what their invention is (a requirement known as claim definiteness), as well as how to make and use it (the disclosure requirements of enablement and written description). Many concerns about the modern patent system stem from failures to enforce these requirements adequately. Patents cannot serve as efficient property rights if no one can determine the boundaries of those rights, and disclosure failures can lead to patents that cover far more than was actually invented. Better enforcement of § 112 may be the best way to address the problem of “patent trolls” asserting overbroad and unclear patents. But despite the critical importance of § 112 to the functioning of the patent system, there is surprisingly little empirical data about how it has been applied in practice. For example, although the conventional wisdom is that courts have reached different outcomes when applying § 112 to different technologies and industries, these assertions are based on only a handful of prominent cases.

To remedy this reliance on anecdotes, we have created a hand-coded dataset of 1,144 reported court decisions from 1982 to 2012 in which U.S. district courts or the Court of Appeals for the Federal Circuit rendered a decision on the enablement, written description, or claim definiteness requirements of § 112. We coded validity outcomes under these three doctrines on a novel five-level scale so as to capture significant subtlety in the strength of each decision, and we also classified patents by technology and industry categories. We also coded for a number of litigation characteristics that could arguably influence outcomes. Although one must be cautious about generalizing from reported decisions due to selection effects, our results show some statistically significant disparities in § 112 outcomes for different technologies and industries, although fewer than the conventional wisdom suggests, and not always in the direction that many have believed. Just as importantly, our analysis reveals the effects of other variables on § 112 outcomes, including whether a district court or the Federal Circuit made the last decision in a case, whether a patent claim was drafted in means-plus-function format, and whether a case was decided before or after Markman v. Westview Instruments (holding that interpretation of patent claims is for the court, not the jury).

Patent disclosure and definiteness have been the focus of much recent debate about the patent system. Commentators have argued, for example, that the written description doctrine should be eliminated and that the enablement and definiteness requirements should be significantly revised, and the Supreme Court set forth a new test for indefiniteness in 2014, the contours of which remain uncertain. Our results on how § 112 has been applied in practice will be helpful in evaluating current proposals for reform, and our rich dataset will enable more systematic future studies of these critical doctrines.

Suggested Citation

Allison, John R. and Ouellette, Lisa Larrimore, How Courts Adjudicate Patent Definiteness and Disclosure (March 19, 2015). Duke Law Journal, Vol. 65, p. 609, 2016, Available at SSRN:

John R. Allison (Contact Author)

University of Texas - McCombs School of Business ( email )

CBA 5.202
University of Texas at Austin
Austin, TX 78712
United States

Lisa Larrimore Ouellette

Stanford Law School ( email )

559 Nathan Abbott Way
Stanford, CA 94305
United States


Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics