Originally uploaded at SSRN.


The U.S. Court of Appeals for the Federal Circuit, in its continuing effort to develop a patent claim construction jurisprudence that yields predictable results, has turned to dictionaries, encyclopedias, and similar sources with increasing frequency. This paper explores, from both an empirical and a normative perspective, the Federal Circuit's effort to shift claim construction to a dictionary-based approach. In the empirical part, we present data showing that the Federal Circuit has, since its own in banc Markman decision in April 1995, used reference works such as dictionaries to construe claim terms with steadily increasing frequency. In addition, and contrary to what one might predict from some of the court's earlier statements justifying reliance on dictionaries in claim construction, the Federal Circuit has relied on general purpose English language dictionaries more than twice as often as it has relied on more technical or specialized reference works. Indeed, the claim construction reference work the Federal Circuit has cited most often is Webster's Third New International Dictionary, which by itself accounts for 25% of all such citations and 36% of all citations to general purpose English language dictionaries and similar sources. After demonstrating that the caprice with which judges currently may choose dictionaries effectively eliminates whatever neutrality and predictability gains the turn to dictionaries can offer, we show that the best route to a dictionary-based approach for settling a claim term's ordinary meaning is an explicit change to the Patent Office rules governing patent examination. Specifically, we propose that the Patent Office require that every patent applicant put her dictionary selections (general purpose and technical) on the record during examination, and that any resulting issued patent state the applicant's dictionary selections on its face. Only with such changes to Patent Office rules can the patent system hope to realize the neutrality and predictability goals that rightly animate the Federal Circuit's turn to dictionaries.