How does the USPTO define “undue experimentation” in patent applications?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The USPTO defines “undue experimentation” in patent applications based on the principle that enablement is not precluded by the necessity for some experimentation. According to MPEP 2164.06:

The test is not merely quantitative, since a considerable amount of experimentation is permissible, if it is merely routine, or if the specification in question provides a reasonable amount of guidance with respect to the direction in which the experimentation should proceed.

Undue experimentation is determined when the experimentation required is unreasonable or excessive, considering the guidance provided in the application and the nature of the invention. It’s a case-by-case assessment based on the Wands factors and the specific circumstances of the invention.