Legal Definitions - actual reduction to practice

Definition: Actual reduction to practice is the demonstration that an invention works as intended and is complete for patent purposes. This can be achieved through physical construction and operation or by filing a patent application that provides enough detail for a person skilled in the art to make and test the invention without undue experimentation.

Example: If an inventor creates a new machine and tests it to ensure that it works as intended, this is an actual reduction to practice. Alternatively, if the inventor files a patent application that includes detailed instructions on how to make and test the machine, this is a constructive reduction to practice.

Explanation: Actual reduction to practice is important in determining priority between inventors competing for a patent on the same invention. It is necessary to demonstrate that the invention works as intended and is complete for patent purposes. This can be achieved through physical testing or by filing a detailed patent application. The examples illustrate the two ways in which actual reduction to practice can be achieved.