Brand had the filing date priority. As junior party, Miller had the burden of proof, and made two arguments for priority: 1) first to conceive and first to reduce to practice; and 2) Miller told Brand about the idea in the first place.

The Board here adjudicated the questions of priority of invention and derivation. Priority of invention is awarded “to the first party to reduce an invention to practice unless the other party can show that it was the first to conceive of the invention and that it exercised reasonable diligence in later reducing that invention to practice.” Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1169 (Fed. Cir. 2006); 35 U.S.C. § 102(g). Priority is a question of law which is determined based on underlying factual determinations. Price v. Symsek, 988 F.2d 1187, 1190 (Fed. Cir. 1993).

The BPAI "denied Miller’s attempt to amend its priority statement to claim an earlier date."

The Board then turned to Miller’s other argument, that Miller was entitled to priority because Brand derived the invention from Miller. Miller’s case for derivation was based primarily on two drawings that Miller allegedly showed Brand before Brand’s own conception.

A party may also assert that the patentee did not invent the patented invention by showing derivation. Id. In an interference proceeding, the person challenging the Senior Party’s priority date bears the burden of proof on derivation and must make two showings. Id. First, he must “establish prior conception of the claimed subject matter.”4 Id. Second, he must prove “communication of that conception to the patentee that is sufficient to enable [him] to construct and successfully operate the invention.” Int’l Rectifier Corp. v. IXYS Corp., 361 F.3d 1363, 1376 (Fed. Cir. 2004) (internal quotation marks omitted). This court reviews a finding of derivation as a question of fact. Gambro Lundia AB v. Baxter Healthcare Corp., 110 F.3d 1573, 1576 (Fed. Cir. 1997).

The Board decision here turns on the second issue—communication. On this issue Brand argues that the Board improperly substituted its own opinion for evidence of the knowledge of one of ordinary skill in the art. We agree. As the Board correctly noted, in this case, “Miller, as the proponent of derivation by Brand . . . bears the burden of proving that one skilled in the art would have been capable, without undue experimentation, of making” [the claimed invention from the provided materials]. The Board rejected as unconvincing the only relevant testimony, Miller’s testimony that he explicitly told Brand how to practice the invention of the count. There was also no testimony from one skilled in the art that the drawings communicated an enabling invention to a skilled recipient of the drawings.

The Board’s conclusion... was not supported by any citation to the record.

Lacking an explanation in the record as to how the depicted flitch or dogs would be arranged to perform the claimed method, the Board substituted its own expertise for record evidence that Miller was obligated to provide. The Board’s finding that an artisan would have known how to [perform the claimed process] does not represent a simple substitution of [components], but detailed inferences as to the... process. The detailed nature of the findings that the Board found necessary to make demonstrates the inappropriateness of its approach. Finally, the path that the Board determined that a skilled artisan would follow has, so far as the record reflects, never been followed.... Under such circumstances the Board’s decision was not supported by substantial evidence in the record.

[I]n the context of a contested case, it is impermissible for the Board to base its factual findings on its expertise, rather than on evidence in the record, although the Board’s expertise appropriately plays a role in interpreting record evidence.

The BPAI slapped by the CAFC for making up its own mind without any evidence to back it up, the appeals court awarded inventorship to Brand, reversing the BPAI decision.