Conception is a critical element in determining inventorship. The MPEP provides guidance on what constitutes conception: "The threshold question in determining inventorship is who conceived the invention. Unless a person contributes to the conception of the invention, he is not an inventor. … Insofar as defining an inventor is concerned, reduction to practice, per se, is irrelevant [except for simultaneous conception and reduction to practice, Fiers v. Revel, 984 F.2d 1164, 1168, 25 USPQ2d 1601, 1604-05 (Fed. Cir. 1993)]. One must contribute to the conception to be an inventor." In re Hardee, 223 USPQ 1122, 1123 (Comm'r Pat. 1984). This means that to be considered an inventor, an individual must contribute to the mental part of inventing - coming up with the idea or solution - rather than just helping to physically create or test the invention. To learn more: conception inventorship patent law invention idea