How are subjective terms in patent claims evaluated?

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.

Subjective terms in patent claims require careful evaluation to ensure definiteness. The MPEP 2173.05(b) states: “When a subjective term is used in the claim, the examiner should determine whether the specification supplies some standard for measuring the scope of the term, similar to the analysis for a term of degree.” An objective standard must be provided to allow the public to determine the claim’s scope. Claims requiring subjective judgment without restriction may be indefinite. For example, in Datamize LLC v. Plumtree Software, Inc., the term “aesthetically pleasing” was found indefinite because it depended solely on subjective opinion without objective boundaries.