Section 103 Obviousness Rejections


Continuing with my discussion yesterday regarding rejection of patent applications based upon the examiner’s assertion that the claimed development is obvious, I am exploring the USPTO updated guidance to examiners published in early 2018.  An invention can not be patented if the development would have been obvious to a person skilled in the art at the time the invention was made.  See 35 U.S.C. Section 103.  

The most common basis of a rejection of a claim/application is that of obviousness under section 103.  The rejection is based upon the examiner’s assertion that the subject matter would have been obvious to a person skilled in the art based upon the prior art technology.

The standard for claiming obviousness was loosened in the 2007 Supreme Court decision of KSR Int’l Co. v. Teleflex, Inc. Although the Court continued its admonition that the examiner could not reject a development based upon hindsight analysis, the Court expressly allowed the examiner to incorporate “common sense” into the analysis.  This increased the subjective analysis permitted the examiner.  The Court made clear, however, that the examiner must provide a factual basis for the determination and not rely on conclusory statement.

Implementation, however, of the principles stated in the KSR decision have been problematic.  The USPTO promulgated revised guidelines published in the Manual of Patent Examination and Procedure (MPEP) section 2143.  This section provided examples of permitted rationales for obviousness.  


MPEP 2143 repeats:

“When setting forth a rejection, Office personnel are to continue to make appropriate findings of fact as explained in MPEP Sections 2141 and 2143, and must provide a reasoned explanation as to why the invention as claimed would have been obvious to a person of ordinary skill in the art at the time of the invention. This requirement for explanation remains even in situations in which Office personnel may properly rely on intangible realities such as common sense and ordinary ingenuity.” 

The USPTO guidelines also provide the following listing of exemplary rationales for rejecting a claim on the basis of obviousness:

Exemplary rationales that may support a conclusion of obviousness include:

  • (A) Combining prior art elements according to known methods to yield predictable results;
  • (B) Simple substitution of one known element for another to obtain predictable results;
  • (C) Use of known technique to improve similar devices (methods, or products) in the same way;
  • (D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results;
  • (E) “Obvious to try” – choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success;
  • (F) Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art;
  • (G) Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention.

Again the USPTO is clear that the employing such rationales must be combined with specific factual findings.  These findings must be communicated to the applicant.

Note also that the examiner can combine and incorporate into the rationale citations to multiple prior art references.  (Note: consistent with my earlier post, all of the references must be within an analogous technology.)  

Also note that the prior art may separately contain all of the claim elements, but the invention will not be obvious if the prior art also contains references suggesting that such combination may not work or produce an unsuitable result.  Further, if the applicant’s combination yields more than the predictable result, the combination is not obvious.  (Again, this is a situation where the text of the specification may be critical.)


The topic of “what is obvious” is broad.  See the exemplary and non-exclusive rationales A-G above.  I intend to expand this discussion in the following days.   Also see my articles Overcoming Obviousness Rejections and 103 Obviousness Rejections II.

Copyright David McEwing, 2019