How does the level of skill in the art affect the written description requirement?

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 level of skill in the art plays a significant role in determining whether the written description requirement is met. The MPEP states:

“The description needed to satisfy the requirements of 35 U.S.C. 112 ‘varies with the nature and scope of the invention at issue, and with the scientific and technologic knowledge already in existence.’”

Key points to consider:

• In mature technologies with a high level of skill, less detail may be required in the written description.
• For emerging or unpredictable technologies, more evidence is typically required to show possession.
• What is considered conventional or well-known to one of ordinary skill in the art need not be described in detail.

Examiners must consider the level of skill in the art when evaluating whether the written description requirement is met.