37 CFR 42.65 : Patents, Trademarks, And Copyrights (Section 2.11 To Chapter V) — United States Patent And Trademark Office, Department Of Commerce (Parts 1 - 199) (Section 2.11 To Parts 151-199) — Unknown Title (Parts 2 - 90) (Section 2.11 To Section 90.3) — Trial Practice Before The Patent Trial And Appeal Board (Section 42.1 To Section 42.407) — Trial Practice And Procedure (Section 42.1 To Section 42.80) — General (Part 42) (Section 42.1 To Section 42.80) — Expert testimony; tests and data.

(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. Testimony on United States patent law or patent examination practice will not be admitted.

(b) If a party relies on a technical test or data from such a test, the party must provide an affidavit explaining:

(1) Why the test or data is being used;

(2) How the test was performed and the data was generated;

(3) How the data is used to determine a value;

(4) How the test is regarded in the relevant art; and

(5) Any other information necessary for the Board to evaluate the test and data.