How does the USPTO evaluate evidence of unexpected results 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 evaluates evidence of unexpected results in patent applications based on several factors. According to MPEP 716.02:

Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected.

To evaluate unexpected results, the USPTO considers:

• The claimed invention’s properties compared to the prior art
• The extent of the unexpected difference
• Whether the unexpected property is superior
• Whether the results occur over the entire claimed range
• Whether the results are commensurate in scope with the claims

Applicants must provide objective evidence to support assertions of unexpected results.