The Federal Circuit reversed a decision from the International Trade Commission (ITC) to allow testimony from a witness offered to provide expert witness testimony from the perspective of a person having ordinary skill in the art (POSITA). The ITC had disallowed testimony from the witness concerning the doctrine of equivalents due to a lack of experience but allowed testimony regarding claim construction and literal infringement.

The Federal Circuit ruled that all of the testimony should be inadmissible as lacking relevant knowledge and amounting to impermissible advocacy from the witness stand, plainly stating 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” and that too much experience was not a bar to testimony.

Although the witness had advanced degrees in engineering and extensive experience in the design and manufacture of fastener driving tools, the witness lacked experience in powered nailer design. And the agreed definition of a POSITA required experience with powered nailer design, rather than fastener driving tools generally. Thus, it was a simple matter for the Federal Circuit to find the witness unqualified.

This case reinforces the need for due diligence to identify an expert witness satisfying the qualifications of a POSITA for testimony regarding claim construction, infringement, and validity. Also, litigants should be on guard for narrow definitions of a POSITA that inadvertently exclude a chosen witness or broad definitions seeking to include unqualified witnesses.

The Federal Circuit addressed other issues in the case, including finding that the term “lifter member” should be interpreted as a “means-plus-function” term under 35 U.S.C. § 112(6) (now 112(f)).