What’s Clear and Convincing to Juries
Litigants seeking to invalidate a patent in federal court face an uphill battle. Last year, the Supreme Court confirmed that, while patent–owners can prove infringement by a mere preponderance of the evidence, accused infringers must prove invalidity by clear and convincing evidence. But what if the Patent Office had never seen the prior art—earlier examples of the patented invention—asserted by the accused infringer? Shouldn’t it matter whether the Patent Office had the chance to review the invalidating before issuing the patent? Without changing the standard of proof, the Supreme Court did acknowledge that it is relevant to the consideration of the invalidity defense whether or not the Patent Office was made aware of the prior art before issuing the patent or not.
In his Chicago IP Litigation Blog, friend–of–the–blog Dave Donoghue highlights a recent study of how juries react when this last factor is introduced into the jury instructions. In their study, two professors presented mock jurors with a fact pattern, a summary of the parties’ arguments, and a randomly assigned set of jury instructions. Set one included a “clear and convincing” instruction. A second set included a “preponderance of the evidence” instruction. The final set included a “clear and convincing” instruction that acknowledged that the burden to prove invalidity could be more easily satisfied if the prior art had not been seen by the Patent Office.
Here is that third instruction in full:
Clear and convincing evidence is evidence that shows it is highly probable that the patent was obvious. This is a higher standard of proof than a preponderance of the evidence, which means more probable than not. However, clear and convincing evidence is lower than the beyond a reasonable doubt standard used in criminal cases.
The burden of proving obviousness is more easily satisfied when, as in this case, the prior art on which the claim of obviousness is based was not considered by the Examiner.
As expected, jurors were more likely to find the patent invalid under the preponderance standard than the clear and convincing standard. Interestingly, however, jurors were just as likely to find the patent invalid under the “clear and convincing”–plus standard as the preponderance standard. As Dave notes, that finding suggests that prior art not presented to the patent office may be more valuable to defendants, and getting the right jury instruction on invalidity really matters.