What is the significance of the term “materially different” in MPEP 806.05(e)?

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 term “materially different” in MPEP 806.05(e) is crucial for establishing distinctness between process and apparatus claims. It implies that:

• The alternative process or apparatus must be substantially different, not merely a slight variation.
• The difference should be meaningful enough to justify separate classification or separate status in the art.
• The alternative must demonstrate that the claimed process and apparatus are not obvious variants of each other.

For example, if an examiner states that “the apparatus as claimed can be used to practice another and materially different process,” they must show that this alternative process is significantly different from the claimed process, not just a minor modification. This helps ensure that restriction requirements are based on substantial distinctions rather than trivial differences.