Herbert Markman owned a patent on a computerized inventory control and reporting system used in retail settings (including dry-cleaning establishments). He sued Westview Instruments, Inc., alleging that Westview's point-of-sale system infringed his patent. The core dispute centered on the meaning of the claim term "inventory," which Markman argued encompassed the tracking of both goods and cash receipts. Westview contended that the patent used "inventory" to refer only to physical articles of merchandise, so its system, which primarily tracked financial information and sales data rather than the movement of goods, did not infringe. At trial, the district court allowed the jury to consider claim meaning and infringement; the jury found for Markman. The court then granted judgment as a matter of law (JMOL) for Westview after construing "inventory" to exclude cash receipts and to be limited to tracking actual articles of inventory—under which construction, Westview's system did not infringe. On appeal, the Federal Circuit (en banc) held that claim construction is a matter of law for the court, affirmed the district court's construction, and sustained the JMOL for Westview. The Supreme Court granted certiorari and affirmed.
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.
The Court conducted a historical and functional analysis. Historically, at common law, the construction of written instruments—such as deeds, contracts, and statutes—was treated as a question of law for judges. Patents are written instruments, and their claims delineate the legal boundaries of the patentee's rights; thus, their interpretation aligns with the traditional judicial function. English and early American practice reflected judges instructing juries on the meaning of patent documents while leaving to juries factual determinations like infringement and damages. The Court found no historical basis for a jury right to construe claim language. Functionally, the Court emphasized that judges are better equipped to interpret complex written documents, particularly when uniformity across cases is essential. Because the meaning of a patent claim affects subsequent cases and parties, assigning claim construction to judges promotes consistent outcomes and predictability in the national patent system. The Court recognized that claim construction may involve assessing extrinsic evidence; however, it characterized this as aiding the court's understanding of the technology and the usage of terms, not as transforming claim construction into a jury question. Accordingly, the Seventh Amendment posed no obstacle to assigning this task to the court, and the district court properly set aside the jury's verdict based on its independent claim construction.
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.
Markman v. Westview Instruments, Inc. reoriented patent trials by assigning the legal task of claim construction to the court. By clarifying that judges, not juries, interpret the language that defines the boundaries of a patent, the Supreme Court advanced uniformity, predictability, and efficiency in patent adjudication.