Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996)
Markman v. Westview Instruments, Inc.
Whether the interpretation of patent claim terms (claim construction) is a question of law for the court, or a question of fact for the jury, under the Seventh Amendment and general principles of adjudication.
Patent claim construction—i.e., interpreting the meaning and scope of patent claim language—is a matter of law to be decided by the court, not by a jury. The Seventh Amendment does not require that juries construe patent claims. In construing claims, courts may consider intrinsic evidence (the claims, specification, and prosecution history) and, where helpful, extrinsic evidence (e.g., expert testimony and treatises), but the ultimate construction remains a legal determination for the judge.
The Supreme Court affirmed the Federal Circuit and held that the construction of patent claims is exclusively for the court. The Seventh Amendment does not mandate that juries interpret patent claim language.
Markman established that claim construction is for the judge, catalyzing the widespread use of pretrial Markman hearings and ensuring that the legal scope of a patent is determined before the factfinder assesses infringement and damages. The case advances uniformity and predictability by centralizing interpretive authority with the court, which in turn facilitates consistent appellate review. For law students, Markman is indispensable: it defines the structure of modern patent trials, shapes litigation strategy, and interacts with later cases (e.g., Teva v. Sandoz) addressing how appellate courts review claim construction. While Teva later clarified that subsidiary factual findings underlying claim construction are reviewed for clear error, Markman's allocation of claim construction to judges remains the bedrock of patent adjudication.