The US Court of Appeals for the Federal Circuit reversed a ruling by the Patent Trial & Appeal Board (Board) where, on appeal, the US Patent & Trademark Office’s (PTO) rationale for sustaining the Board’s obviousness rejection did not reflect “the reasoning or findings the Board actually invoked.” In Re Google, LLC, Case No. 22-1012 (Fed. Cir. Jan. 9, 2023) (Moore, C.J., Lourie, Prost, JJ.)

Google’s patent application covers a method of filtering search results to display age-appropriate results using a “content rating score” in combination with a predetermined threshold value to determine which results will be presented. The application discloses several ways that the threshold value can be calculated, including using the length of the search query as a proxy for the age of the user, with longer queries being associated with older users and leading to a lower threshold score (allowing more mature content to be shown).

The application received a final rejection from the examiner, who asserted that the claims would have been obvious under 35 U.S.C. § 103 based on two prior art references, Parthasarathy and Rose. Parthasarathy disclosed a method to determine a content score to use for ranking results, while Rose disclosed a method to assign result importance based on query length. The examiner argued that it would be obvious to combine Rose and Parthasarathy to achieve the claimed method that recited a “predetermined threshold value” based on the number of words in a query. The examiner acknowledged that Parthasarathy did not disclose a threshold based on a number of words but found that Rose did, citing Rose’s modified relevance-ranking algorithm. He reasoned that it would have been obvious to combine Rose and Parthasarathy to achieve the claimed threshold because “analyzing a query for determining the query length and using the query length as a threshold is very well known in the art and doing so would further provide for assigning weight to a long or a short query for retrieving documents.” Google appealed the examiner’s decision to the Board, which affirmed the examiner’s rejection and adopted the examiner’s findings. Google appealed to the Federal Circuit.

On appeal, the PTO argued that because there were only two ways a person of ordinary skill in the art could modify Parthasarathy’s threshold to incorporate Rose, either of the modifications would have been obvious. However, the Federal Circuit found that this argument was not supported by the Board’s decision. The Court explained that while the Board did conclude that modifying Parthasarathy’s threshold to take into account the length of the query would have been obvious, the Board did not provide any detail as to how that would be achieved. In the absence of specific fact-based findings by the Board, the Court explained that it could not adopt the PTO’s argument, which rested on facts not found in the Board’s decision. A ruling relying on these facts would have resulted in a violation of basic administrative law principles since a court may only uphold an agency action on the grounds that the agency invoked when taking that action (citing the 2015 Supreme Court of the United States decision in Michigan v. EPA).

The Federal Circuit vacated the Board’s decision (citing a lack of “expressed reasoning”) and remanded the case.