Legal Definitions - objective but-for test

The objective but-for test is a method used in patent law to determine the materiality of withheld information. It is used to assess whether the withheld information, if disclosed, would have resulted in a finding of unpatentability.

For example, if an applicant for a patent withholds information that is crucial to the patent's validity, the objective but-for test would determine whether the patent would have been granted if that information had been disclosed.

It is important to note that there is also a subjective but-for test, which focuses on whether the misrepresentation caused the examiner to issue the patent. However, the Federal Circuit has rejected this test in favor of the materiality test codified in 37 CFR § 1.56.

Overall, the objective but-for test is a way to determine whether a patent was granted based on incomplete or misleading information, and whether it would have been granted if all relevant information had been disclosed.