What is the Burden of Proof when practicing before the Board of Patent Appeals? – Florida Patent Lawyer Blog

Written by Mark Terry

In short, the answer is “by a preponderance of the evidence.” The Board of Patent Appeals and Interferences (BPAI) decision of Ex parte Hochsmann did a good job of highlighting this axiom. As a Miami Patent Lawyer, I found the Ex parte Hochsmann decision interesting because it reminded me of the burden I must carry when I practice before the BPAI.

The case of Ex parte Hochsmann involved a chemical process including salt crystals. The principal issue in this appeal was whether Appellant had established that the Examiner erred in finding that the prior art reference would have disclosed a salt crystal. But how far must the Appellant go in showing that the Examiner erred?

The Board found: “We are of the opinion Appellant’s arguments do not establish that the evidence in the totality of the record weighs in favor of the nonobviousness
of the claimed procedure.” The Board went on: ” Accordingly, based on our consideration of the totality of the record before us, we have weighed the evidence of obviousness found in the combined teachings of [the prior art] with Appellant’s countervailing evidence of and argument for nonobviousness and conclude, by a
preponderance of the evidence and weight of argument, that the claimed
invention … would have been obvious as a matter of law under 35 U.S.C. § 103(a).”

That pretty much says it: your burden of proof before the Board of Patent Appeals is a “preponderance of the evidence.” What does that mean?

Preponderance of the evidence, which is one of the lower burdens to meet, is also known as balance of probabilities is the standard required in most civil cases. The standard is met if the proposition is more likely to be true than not true. Effectively, the standard is satisfied if there is greater than 50 percent chance that the proposition is true. It can be described simply as “more probable than not.”

Lessons Learned: What does this mean to practitioners? This means that in order to reverse an Examiner’s decision at the BPAI, you must present slightly more evidence than the Examiner. Technically, that should suffice. Of course, in practice, you probably want to show a bit more, to make it clear you have met your burden


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