It is often unclear when a prior occurrence or disclosure of a claimed invention falls under the patent law doctrines of inherent or accidental anticipation. Courts have applied various tests in determining whether anticipation is inherent or accidental, and the cases are difficult to reconcile. Tests seemingly dispositive to establish an accident in one case may also appear dispositive to establish inherency. As a result of our analysis, we have developed a two-step test that can be used to reconcile the two doctrines and determine whether a product or process anticipates. The first prong is concerned with whether the prior process or composition was useful in the art. If the answer to the first prong is no, then the anticipation is accidental; if the answer is yes, the second prong is whether the process or composition occurred under unusual conditions or occasionally. If the answer to the second prong is no, then the anticipation is inherent; if the answer is yes, then the anticipation is accidental. This test helps resolve the confusion about inherent and accidental anticipation while remaining consistent with Supreme Court, Federal Circuit and CCPA decisions.
Anne Brown and Mark Polyakov, The Accidental and Inherent Anticipation Doctrines: Where Do We Stand and Where Are We Going?, 4 J. Marshall Rev. Intell. Prop. L. 63 (2004)