Obviousness is the requirement that sinks more patent applications than any other. Under 35 U.S.C. § 103, an invention cannot be patented if the differences between it and the prior art would have been obvious to a person of ordinary skill in the field at the time the application was filed, even when no single earlier reference discloses the invention.
This is what separates § 103 from novelty under § 102. Novelty is a matching exercise: does one prior reference already contain every element of the claim? Obviousness is a judgment call: would an ordinary practitioner, holding all the relevant prior art in front of them, have gotten here anyway? Nearly every invention is new in the trivial sense that nobody assembled exactly those parts before. Section 103 exists to keep that trivial newness from earning a twenty-year monopoly.
The operative text is short. A patent may not be obtained if “the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains.”
Three phrases carry the weight. “As a whole” forbids picking the invention apart and declaring each piece old, which is how almost everything looks obvious. “Before the effective filing date” fixes the analysis in the past, which matters enormously because the finished invention makes its own path look inevitable. And “person having ordinary skill in the art” installs a hypothetical benchmark rather than the actual inventor or the actual examiner. The statute also states that patentability “shall not be negated by the manner in which the invention was made,” which retired the old judicial notion that a patent required a flash of genius rather than plodding work.
The Supreme Court gave § 103 its operating procedure in Graham v. John Deere Co., 383 U.S. 1 (1966), decided thirteen years after Congress enacted the statute in 1952. Obviousness is a question of law, the Court held, but it rests on four factual inquiries that are still the skeleton of every examination and every validity trial:
The Court was explicit that these are factual questions, which is why obviousness fights are so evidence-heavy despite being a legal conclusion. In the Graham case itself, the patent covered a spring clamp for a plow shank, and the Court found the rearrangement obvious over the inventor’s own earlier patent.
The PHOSITA is a legal construct, not a real person, and it does most of the hidden work. This hypothetical practitioner is presumed to know all the pertinent prior art, worldwide, including obscure references no working engineer would ever find. But the PHOSITA is an ordinary practitioner, not an innovator: competent, well read, unimaginative.
Where the level of skill gets set determines outcomes. Define the field’s ordinary practitioner as a PhD chemist with ten years at the bench and more looks obvious. Define them as a technician with a two-year degree and less does. This is why parties in litigation fight over PHOSITA definitions that sound like formalities. KSR added an important gloss: a person of ordinary skill is “a person of ordinary creativity, not an automaton,” and can fit teachings together like pieces of a puzzle.
For roughly a quarter century the Federal Circuit policed obviousness with the teaching, suggestion, or motivation test, an idea it inherited from its predecessor the Court of Customs and Patent Appeals: to combine two references, you had to point to something in the prior art, the nature of the problem, or the knowledge of a skilled person that actually suggested the combination. Applied strictly, TSM was a shield. Few prior art documents helpfully announce “combine me with that other reference.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), ended the rigid version. The patent Teleflex asserted, the Engelgau patent, claimed in its claim 4 an adjustable vehicle pedal with an electronic pedal position sensor attached to a fixed pivot point. Both halves were old. The district court held the claim obvious on summary judgment, and the Federal Circuit revived it by faulting that court’s TSM analysis. The Supreme Court reversed, holding claim 4 obvious and holding that the obviousness inquiry must be “expansive and flexible.”
The reasoning that survives KSR and drives examination today:
KSR is the reason obviousness became the most common rejection an applicant faces, and the reason examiners can assert combinations backed by reasoning rather than a citation.
Objective indicia are the applicant’s best counterweight, because they are real-world facts rather than argument: commercial success, long-felt but unsolved need, failure of others, copying by competitors, industry praise, skepticism of experts, and unexpected results. The Federal Circuit treats them as a required part of the record when presented, not an optional afterthought.
They fail more often than they work, and the usual cause is nexus. The evidence has to tie to the claimed features. A product that sold a hundred million units proves nothing about non-obviousness if the sales came from a marketing budget, a brand, a distribution deal, or an unclaimed feature. Unexpected results, meanwhile, must be a difference in kind or a genuinely surprising difference in degree, compared against the closest prior art rather than a convenient one.
What does obviousness mean in patent law? Obviousness under 35 U.S.C. § 103 bars a patent when the differences between the invention and the prior art would have been obvious to a person of ordinary skill in the field at the time of filing. It is separate from novelty. Novelty asks whether one prior reference already discloses the invention. Obviousness asks whether a skilled person would have combined or modified what already existed to arrive at it.
What are the Graham factors? From Graham v. John Deere Co., 383 U.S. 1 (1966), four inquiries: the scope and content of the prior art, the differences between the prior art and the claims, the level of ordinary skill in the pertinent art, and secondary considerations such as commercial success, long-felt but unsolved need, and the failure of others. The first three are the core analysis; the fourth is objective evidence that can rebut a case of obviousness.
What did KSR v. Teleflex change? KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), rejected the Federal Circuit’s rigid application of the teaching, suggestion, or motivation test. The Supreme Court held the analysis must be expansive and flexible, that combining known elements to yield predictable results is likely obvious, and that common sense, market pressure, and design incentives can supply the reason to combine even when no prior art document states it.
How do you overcome an obviousness rejection? Three main routes: show the examiner misread a reference or that the combination does not actually teach every claim element; argue the proposed combination yields unpredictable results, destroys the purpose of a reference, or that the art teaches away from it; or submit objective evidence of non-obviousness such as commercial success, long-felt need, or unexpected results. That evidence must have a nexus to the claimed features, not to marketing or an unclaimed advantage.
Going further: What Is Patentable? The four requirements explained .
This page is general legal information, not legal advice, and it does not create an attorney-client relationship.
The Supreme Court voided a clay doorknob patent for want of invention, creating the 'ordinary mechanic' standard that Graham and Section 103 later codified.
The Federal Circuit held that secondary-considerations evidence lacks nexus when the feature driving a product's success was already disclosed in the prior art.
The Supreme Court's first reading of Section 103 set the durable framework for judging obviousness: scope of the prior art, differences, level of skill, and secondary considerations.
The Federal Circuit reversed a PTAB obviousness finding because the petitioner showed the prior art's pieces existed but never explained why a skilled artisan would assemble them that way.
The Federal Circuit reversed a PTAB win for the patentee, holding that a claimed range overlapping the prior art creates a presumption of obviousness that applies in inter partes review just as in court.
The Federal Circuit vacated an obviousness judgment because the trial court declared the claims obvious first and only then asked whether objective indicia could rescue them.
The Supreme Court replaced the Federal Circuit's mechanical teaching-suggestion-motivation test with a flexible, common-sense obviousness inquiry that still governs every Section 103 dispute today.
