REDUCTION TO PRACTICE
reduction to practice.Patents. The embodiment of the concept of an invention, either by
physical construction and operation or by filing a patent application with a disclosure adequate to
teach a person reasonably skilled in the art how to make and work the invention without undue
experimentation. • The date of reduction to practice is critical in determining priority between
inventors competing for a patent on the same invention. See INVENTION. [Cases: Patents 90(5).
C.J.S. Patents § 123.]
actual reduction to practice.The empirical demonstration that an invention performs its
intended purpose and is therefore complete for patent purposes; the use of an idea or invention —
as by testing it — to establish that the idea or invention will perform its intended purpose.
Brunswick Corp. v. U.S., 34 Fed. Cl. 532, 584 (1995).
constructive reduction to practice.The documented demonstration that an invention will
perform its intended purpose, contained in a patent application that provides enough detail that a
person skilled in the art could make and test the invention; the filing of a patent application for an
invention or design. Brunswick Corp. v. U.S., 34 Fed. Cl. 532, 584 (1995). [Cases: Patents 90(5).
C.J.S. Patents § 123.]
vicarious reduction to practice.A doctrine that treats one party’s actual reduction to practice of
an invention as the opposing (usu. complaining) party’s actual reduction to practice. • In a
two-party interference, proof of derivation is usu. sufficient; showing an actual reduction to
practice is unnecessary. The doctrine is more important in a three-party interference. [Cases:
Patents 90(5). C.J.S. Patents § 123.] [Blacks Law 8th]