By Tony Pezzano and Michael Dougherty ( November 29, 2018, 12:52 PM EST) -- The Graham v. John Deere[1] standard for evaluating the obviousness of a claimed invention has been in place for over 50 years. The traditional Graham v. John Deere approach requires analysis of four factors: (1) the scope and content of the prior art; (2) the differences between the prior art and the patent claims; (3) the level of ordinary skill in the art; and (4) secondary considerations (also known as "objective indicia" of nonobviousness). U.S. Supreme Court and Federal Circuit case law require that all four factors be evaluated collectively before a conclusion on obviousness is reached. The cases also require that the burden of proving obviousness is on the patent challenger and never shifts....