The Analogous Art Test: A Natural Alternative to the Slippery Slope of Hindsight Bias

By: A. Rusty Rogers


When cobbling together references to establish a prima facie case of obviousness, the Patent and Trademark Office (PTO) is under the burden to establish that the prior art selected also satisfies what is reasonable to assume that a skilled artisan would consult during the inventive process, also known as the “analogous art test.”  In a case involving use of molasses for de-icing roads, the Federal Circuit has shed new light on this sticky subject.

During patent prosecution, examiners at the PTO often attempt to show that a claim is not patentable by finding each claim limitation in a single reference or by combining multiple prior art references where a single document is not sufficient.  However, all too often the PTO will simply grab elements to establish a prima facie case of obviousness from references without regard to consideration of the natural inventive process and what artisans would normally consider when inventing a novel solution to a problem.  Enter the analogous art test.  As explained in In re Bigio, 381 F.3d 1320, to be considered prior art, the PTO is under the burden to establish that a reference is (1) from the same field of endeavor, regardless of the problem addressed, or (2) reasonably pertinent to the particular problem with which the inventor is involved.

This principle is highlighted in a recent decision from the Court of Appeals of the Federal Circuit (CAFC), In re Natural Alternatives, 2015-1911 (August 31, 2016) before Newman, Clevenger, and O’Malley, which centered around U.S. Patent No. 6,080,330 (‘330 patent) issued to Natural Alternatives, LLC (Natural), directed to the use of desurgared beet molasses (DSBM) for de-icing roads.  In an unpublished opinion, the CAFC reversed the Patent Trial and Appeal Board’s (PTAB) affirmation of the PTO’s invalidation of the ‘330 patent as obvious over a combination of references during reexamination. Ultimately, the CAFC sided with Natural, finding that the primary reference taught the use of a molasses containing 50% sugar, which was distinguishable from the DSBM used in the ‘330 patent.

However, the CAFC also revisited the analogous art test during when confronting Natural’s argument of whether a reference teaching the use of DSBM constituted prior art for obviousness purposes and took the time to fault the USPTO and the PTAB for failing to provide a reason why a person of ordinary skill in the art would have consulted the particular reference.   The secondary reference in question was directed to the use of DSBM in “a wheel having a pneumatic tire filled with liquid molasses as a ballast,” a far cry from the compositions in ‘330 which were to be applied directly to roads for deicing.  Here, the CAFC reiterated that the burden lies with the PTO to explain how the reference lies in the same field of endeavor or is reasonably pertinent to the particular problem.

In practical application, the analogous art test may be asserted defensively by alerting the PTO to their burden to satisfy the test, while characterizing the field of the invention in a reasonable way that favors the applicant or attacking the “pertinence” of the reference if in the same field.  It is important to note here that how the “same field” or “reasonably pertinent” are framed can affect the outcome of the test.  For example, the PTO made a last ditch attempt to argue that the references were in the same field as relating broadly to “the transportation industry.”  Unpersuaded, the CAFC clarified the issue and discarded the reference by noting the outcome in In re Clay, 966 F.3d 656, in which the reference in question was directed to the extraction of oil, while the invention was directed to the storage of oil.  In Clay, the CAFC held that a prior art reference was not “within Clay’s field of endeavor merely because both relate to the petroleum industry.”

Other notable issues encountered in Natural include revisiting the requirements for secondary considerations (objective indicia) to rebut a finding of obviousness.  Objective indicia of nonobviousness may be used to counter a finding that an ordinarily skilled artisan would have been motivated to combine prior art references across disparate fields.  During reexamination, Natural presented objective evidence from several municipalities of industry praise, commercial success, and licensing for a commercial embodiment of the ‘330 patent.  The USPTO and PTAB contended, however, that there was insufficient “nexus” between the objective evidence and the claims at issue, because all elements of the claims were deemed prior art.  While the CAFC agreed with the USPTO that “[i]f commercial success is due to an element in the prior art, no nexus exists.” Tokai Corp. v. Easton Enterprises, Inc., 632 F.3d 1358, 1369 (Fed. Cir. 2011), the CAFC took issue with the USPTO and PTAB’s dismissal of the objective evidence presented by Natural because a prima facie case of obviousness had not been established.  Particularly, the prior art taught molasses in general, but not DSBM in particular, to deice road surfaces.