4813-B Eisenhower Ave. Web: www.Neifeld.com
August 16, 2002
Re: Law of Corroboration
Dear Mr. Zarfas:
I enjoyed reading Mr. Ciraolo's article in the July 2002 edition of the JPTOS, which is entitled "Application of the Corroboration Requirement to Interference Proceedings and Other Sections of 102." For the benefit of the patent bar, I must point out the following inaccuracies in the article.
Mr. Ciraolo states that "A party that conceives of the invention first but reduces it to practice last must show that it exercised diligence, which consists of a continual effort without any reasonable delay, just prior to the other party's entry into the field until their own reduction to practice to be awarded priority. [footnote 4 omitted] This inventor will be considered the junior party and bear the burden of proof during the interference proceeding." 84 JPTOS 531-32; emphasis added. That statement is incorrect. The junior party is defined by the declaration of the interference based solely upon filing dates, which has nothing to do with proof of either actual reduction to practice or diligence. See 37 CFR 1.601(m). Thus, the ultimate burden of proof on priority is established based upon filing dates. See 37 CFR 1.657 and Brown v. Barbacid, 276 F.3d 1327, 1333, 61 USPQ2d 1236, ___ (Fed. Cir. 2002).
Mr. Ciraolo states that "It has been held that one co-inventor may not corroborate the evidence of another co-inventor," citing to Larson v. Johenning, 17 USPO2d 1610, 1613 (PTOBPAI 1990). 84 JPTOS 533. That statement is misleading to the extent "co-inventor" implies a named inventor. In fact, Larson stands for the proposition that a named inventor can corroborate if shown by convincing evidence to not be an inventor of the subject matter defined by the count. Larson explains that the foregoing proposition is a consequence of the change in 35 USC 116 enabling applications to be filed naming more than one applicant even when "each [applicant] did not make a contribution to the subject matter of every claim of the patent." Thus, Larson indicates that a co-inventor may corroborate evidence of another inventor under appropriate circumstances.
Richard A. Neifeld
 Larson at 613 ("In other words, the burden is on the party asserting that the joint applicant relied upon as a corroborating witness is not a joint inventor of the subject matter of the count to establish that fact through convincing evidence in the record. Cf. Vanderkooi v. Hoeschele, 7 USPQ2d 1253, 1256 (BPAI 1987).").