How does the USPTO determine if an art is predictable or unpredictable?

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 determines whether an art is predictable or unpredictable based on the ability of a skilled artisan to anticipate the effects of changes within the subject matter. According to MPEP 2164.03:

“If one skilled in the art can readily anticipate the effect of a change within the subject matter to which the claimed invention pertains, then there is predictability in the art. On the other hand, if one skilled in the art cannot readily anticipate the effect of a change within the subject matter to which that claimed invention pertains, then there is lack of predictability in the art.”

The determination often relies on the nature of the technology and the existing knowledge in the field. For example:

• Mechanical and electrical arts are generally considered more predictable.
• Chemical reactions and biological systems are often considered less predictable.

This assessment impacts the level of disclosure required to meet the enablement requirement in patent applications.