In Kyocera Senco Industrial Tools Inc. v. International Trade Commission, the Federal Circuit held in a precedential opinion that expert witnesses must at least have ordinary skill in the art. Because Kyocera’s expert did not have the particular experience required for ordinary skill in the art, the Court held that the administrative law judge (ALJ) abused his discretion by admitting the expert’s testimony on issues analyzed through the lens of a skilled artisan.

In 2017, Kyocera Senco Industrial Tools Inc. (“Kyocera”) filed a complaint at the International Trade Commission (ITC) alleging that Koki Holdings America Ltd. (“Koki”) was violating 19 U.S.C. § 1337 by importing certain gas spring nailer products, or nail guns, that infringe certain claims in five patents. The patents at issue generally relate to portable tools that drive staples, nails, or other linearly driven fasteners.

During claim construction, the ALJ adopted Koki’s definition of a skilled artisan, which required a minimum of two years’ experience designing power nailers. Kyocera offered Dr. Pratt as a technical expert on claim construction, invalidity, literal infringement, and infringement under the doctrine of equivalents. Dr. Pratt has advanced degrees in engineering, and extensive experience in the design and manufacture of fastener driving tools—but he lacked experience in power nailer design specifically.

Because of this, Koki moved to exclude Dr. Pratt’s testimony on the grounds that he was incapable of analyzing the issues from the perspective of a skilled artisan. The ALJ found that Dr. Pratt did not meet the requirements for a skilled artisan, but noted that Federal Circuit case law appeared to be inconclusive on whether Dr. Pratt’s testimony should be excluded. Finding no case directly on point, the ALJ excluded Dr. Pratt’s testimony on infringement under the doctrine of equivalents. Curiously however, the ALJ admitted Dr. Pratt’s testimony on literal infringement.

On appeal, the Court held, “[t]o offer expert testimony from the perspective of a skilled artisan in a patent case—like for claim construction, validity, or infringement—a witness must at least have ordinary skill in the art.”[i] The Court reasoned that, without ordinary skill, “the opinions would not be based on any specialized knowledge, training, or experience that would be helpful to the factfinder.”[ii] The Court further reasoned that this is true regardless of whether the testimony is directed to literal infringement or infringement under the doctrine of equivalents. “Nothing about literal infringement makes an unqualified witness’ testimony more relevant or reliable… The absence of relevant knowledge and the risk for abuse apply equally to both situations.”[iii]

The Court found their opinion in Endress + Hauser, Inc. v. Hawk Measurement Sys. Pty. Ltd. to be consistent with their opinion here.[iv] According to the Court, Endress recognized that “it would be improper to require an expert witness to possess ordinary skill in the art and nothing more.”[v] But Endress also recognized that “to testify as an expert, a witness must be qualified.[vi] Thus, the Court concluded that “to be qualified to offer expert testimony on issues from the vantage point of an ordinarily skilled artisan in a patent case, an expert must at a minimum possess ordinary skill in the art.”[vii] And because Dr. Pratt lacked ordinary skill in the art—based on his lack of experience in power nailer design—the Court held “the ALJ abused his discretion by admitting Dr. Pratt’s testimony on any issue that is analyzed through the lens of an ordinarily skilled artisan.”[viii]

Although this case was decided on appeal from the ITC, it has a number of implications for District Court and Patent Trial and Appeal Board litigation, and even original, reissue, and reexamination prosecution. Patent challengers and owners should pay close attention to their own experts’ qualifications in view of the scope of the proposed and/or adopted levels of ordinary skill in the art. An expert that has extensive education and general industry experience may still not be an ordinarily skilled artisan if the level of ordinary skill in the art is crafted narrowly enough. Offensively, practitioners on both sides should seek to exclude an opposing expert’s testimony if he does not meet the narrowly crafted qualifications for a skilled artisan. Patent challengers and owners may also have additional opportunity to specifically craft the level of ordinary skill in the art around the experience of the expert supporting a petition.


[i] Slip Op., 11.

[ii] Id.

[iii] Id.

[iv] 122 F.3d 1040, 1042 (Fed. Cir. 1997).

[v] Slip Op., 12 (emphasis in original).

[vi] Id.

[vii] Id.

[viii] Id.


This article appeared in the January 2022 issue of PTAB Strategies and Insights. To view our past issues, as well as other firm newsletters, please click here.

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