HGF Presents
Unclear Claim Parameters
September 2025
Video overview:
Patent claims must be clear enough for a skilled person to determine scope and measure any parameters without ambiguity. If a parameter is used, the measurement method must be included in the claim unless it’s common general knowledge, all known methods yield the same result, or including it would reduce clarity—in which case referencing the description is acceptable.
Objections arise when parameters are unusual, require uncommon equipment, or cannot be compared with prior art. Unclear parameters, such as particle size, viscosity, or polymer molecular weight, often lead to refusals. Removing unclear parameters may unintentionally broaden claim scope, creating added matter issues.
To avoid problems, define parameters with correct units, describe reproducible measurement methods, and reference industry standards where applicable. Ensure methods are not limited to specific embodiments for broader applicability and clarity.



