are generally inconvenient. Now if a monopoly were allowed in a useless invention other persons would be prevented from improving it or turning it to any account whatever so that combinations of utility might be impeded. It would stand in the way of real inventors and hence be mischievous to the public generally. Burden of proof during prosecution During patent prosecution, the disclosed utility is presumed valid. The patent office bears the burden to disprove utility. The standard the USPTO uses is whether it is more likely than not that it would lack utility from the perspective of a person having ordinary skill in the art. If the examiner shows evidence that the invention is not useful, the burden shifts to the applicant to prove utility. The applicant can then submit additional data to support a finding of utility. The invention must possess utility at the time of application. See also Diamond v. Diehr Incredible utility Reduction to practice State Street Bank v. Signature Financial Group Sufficiency of disclosure Utility in Canadian patent law Utility model Notes and references External links 2107 Guidelines for Examination of Applications for Compliance with the Utility Requirement (USPTO website) United States patent law