No Weight For Unsupported Expert Witness Testimony

• Jurisdiction: United States,Federal
• Law Firm: Marshall, Gerstein & Borun LLP
• Subject Matter: Intellectual Property, Patent
• Author: Mr Sandip H. Patel
• Published date: 22 February 2023

In early February 2023, the Patent Office's Director designated as precedential the Patent Trial and Appeal Board's decision in Xerox Corp. v. Bytemark, Inc., IPR2022-00624, Paper 9 (PTAB Aug. 24, 2022). In this decision, the Board denied a petition seeking inter partes review. The petitioner asserted the challenged patent claims were obvious over printed publication prior art. One of the claimed features was not asserted to be disclosed in the published prior art, but rather asserted to be part of an ordinarily skilled artisan's common knowledge. The Board characterized this as a "conclusory assertion," and gave little weight to the accompanying expert witness's declaration cited in support. Why? Because the declaration, according to the Board, "merely repeats, verbatim, the conclusory assertion for which it is offered to support," and "does not cite to any additional supporting evidence or provide any technical reasoning [in] support." Id. at 15.

The Board further explained that such a declaration "is particularly problematic in cases where, like here, expert testimony is offered not simply to provide a motivation to combine prior-art teachings, but rather to supply a limitation missing from the prior art." Id. at 16. Such a declaration is entitled to weight where the missing limitation is "unusually simple and the technology particularly straightforward," but the petitioner neither alleged that nor offered support for such an allegation. Id.

This is not a controversial decision. After all, the Board's rules caution that such a declaration may be given little or no weight. See 37 C.F.R. ' 42.65(a) ("Expert testimony that does not disclose the underlying facts or data on which the opinion is based is entitled to little or no weight."). And Federal Circuit decisions have also explained this potential. See...