An Empirical Study of the Role of the Written Description Requirement in Patent Examination

Crouch, Dennis | May 16, 2010

An en banc Federal Circuit recently confirmed that § 112 of the Patent Act, as properly interpreted, includes a written description requirement that is separate and distinct from the enablement requirement. The written description and enablement doctrines both encourage applicants to fully disclose their inventions, but the doctrines respectively focus on proof that the patentee (1) has possession of the invention; and (2) has enabled others to make and use the invention. The en banc-challenger argued instead that the patent statute spells out a unified requirement of a written description that enables and that the separate written description requirement should be eliminated. The U.S. Patent & Trademark Office (USPTO) is the executive branch agency tasked with the responsibility of examining patent applications to determine whether patent rights should issue. Once a patent issues, the constitutionally guaranteed exclusive rights can be enforced in federal courts. Although the USPTO has no direct role in the infringement dispute between the patentee Ariad and the accused infringer Eli Lilly, the government submitted an amicus curiaebrief indicating its continued support for the written description requirement as a tool that the USPTO uses to eliminate claims during the patent examination process. The government argued in its brief that a separate written description requirement is “necessary to permit USPTO to perform its basic examination function.” However, when pressed during oral arguments, the government could not point to any direct evidence supporting its contention. This Essay presents the results of a retrospective empirical study of the role of the written description requirement in patent office examination practice. It is narrowly focused on rebutting the USPTO’s claim that the separate written description requirement serves an important role in the patent prosecution process. To the contrary, my results support the conclusion that it is indeed “exceedingly rare that the patent office hangs its case on written description.”