How does the “rule of reason” apply to corroboration of conception in patent cases?

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.

How does the “rule of reason” apply to corroboration of conception in patent cases?

The “rule of reason” is an important principle in evaluating corroboration of conception in patent cases. According to MPEP 2138.04:

“An evaluation of all pertinent evidence must be made so that a sound determination of the credibility of the inventor’s story may be reached.”

This means that when assessing whether there is sufficient corroboration of conception:

• All available evidence must be considered
• The credibility of the inventor’s account is crucial
• There is no rigid requirement for a specific type of evidence

The rule of reason allows for flexibility in evaluating corroboration, recognizing that different situations may require different types of evidence. It emphasizes a holistic approach to determining whether the inventor’s claim of conception is credible and supported by the available evidence.