How does the size of a prior art genus affect obviousness analysis?

The size of a prior art genus is a factor to consider in obviousness analysis, but it’s not determinative on its own. As stated in MPEP 2144.08:

“Consider the size of the prior art genus, bearing in mind that size alone cannot support an obviousness rejection. There is no absolute correlation between the size of the prior art genus and a conclusion of obviousness.“

This means that while a smaller genus might make a species more obvious, it’s not a guarantee. Examiners must consider other factors like:

• The structural similarities between the genus and claimed species
• Any teaching or suggestion to select the claimed species
• The predictability of the technology
• The properties and utilities of the prior art genus

A thorough analysis considering all relevant factors is necessary to establish obviousness.

To learn more:

• obviousness
• prior art genus
• species claims
• patent examination