Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996), is a United States Supreme Court case on whether the interpretation of patent claims is a matter of law or a question of fact.

Opposing results in cases with similar facts were common, and a perception arose that the outcome of such trials was somewhat arbitrary.

In Markman, the Court held that judges, not juries, would evaluate and decide the meaning of the words used in patent claims.

Judges were to look at four sources for definitions, in order of priority: This case has had a significant impact on the patent litigation process in the United States.

[citation needed] In a unanimous ruling written by Justice David Souter, the court affirmed the judgment of the circuit court, holding that: Markman was represented in the original trial by the law firm of Duane Morris,[2] and by the law firm of Eckert Seamans on appeal.