Obviousness is a question of law based on underlying factual inquiries. The factual inquiries, as enunciated by the Supreme Court, are as follows:   1. Determining the scope and content of the prior art; 2. Ascertaining the differences between the claimed invention and the prior art; and, 3. Resolving the level of ordinary skill in the pertinent art.   In addition to the above-described factual inquiries, the United States Patent and Trademark Office (USPTO) is required to evaluate objective evidence of non-obviousness when it exists. These so-called “secondary considerations” may include evidence of commercial success, long-felt but unsolved needs, failure of others, and unexpected results. Knowing whether an invention will be considered nonobvious by the patent examiner is difficult because it is such a subjective exercise—what one patent examiner considers surprising, another may not. In addition, the examiner will usually be asked to make the nonobviousness determination well after the date of the invention, because of delays inherent in the patent process. The danger of this type of retroactive assessment is that the examiner may unconsciously be affected by the intervening technical improvements. To avoid this, the examiner generally relies only on the prior art references (documents describing previous inventions) that existed as of the date of invention.   In assessing the scope and content of the prior art, the Examiner is expected to give the claims the broadest reasonable interpretation consistent with the specification. The law also charges a hypothetical person with ordinary skill in the art with knowledge of all of the pertinent prior art known at the time of invention. Factors that may be considered in determining the level of ordinary skill in the art include: (1) Type of problems encountered in the art; (2) prior art solutions to those problems; (3) rapidity with which innovations are made; (4) sophistication of the technology; and (5) educational level of active workers in the field. In a given case, every factor may not be present, and one or more factors may predominate.   The Supreme Court and the USPTO have enunciated several different rationales upon which obviousness-type rejections may be supported. Prior art is not limited just to the references being applied, but includes the understanding of one of ordinary skill in the art. With this in mind, it should be appreciated that rejections based on obviousness cannot be sustained by mere conclusory statements; instead there must be some articulated reasoning with some rational understanding to support the legal conclusion of obviousness. These rationales may include one or more of the following:   (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 would have been 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.   This is why the search is done in the first step of the patent application process – in order to determine if the invention is new, useful, and the potential for obviousness.