What are secondary considerations of non-obviousness?

Secondary considerations of non-obviousness (also called objective indicia of non-obviousness) are a category of real-world evidence that can rebut a prima facie case of obviousness in U.S. patent prosecution and litigation. Rather than focusing on what the prior art teaches in the abstract, they direct attention to objective facts about the invention's reception and impact: did competitors try and fail? Did experts doubt it would work? Did the market reward it? These facts can supply evidence that a skilled artisan would not have found the invention obvious, because the world itself struggled to arrive at it.

Legal foundation

The underlying patentability standard is 35 U.S.C. § 103: 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 to a person having ordinary skill in the art.

Graham v. John Deere Co., 383 U.S. 1 (1966), established four factual inquiries that must be addressed in every obviousness determination: (1) the scope and content of the prior art; (2) the differences between the prior art and the claims at issue; (3) the level of ordinary skill in the pertinent art; and (4) objective indicia of non-obviousness, including commercial success, long-felt but unsolved needs, and failure of others. Secondary considerations are this fourth factor and may be used to give light to the circumstances surrounding the origin of the claimed invention.

Because all four Graham factors are part of a single unified inquiry, secondary considerations are not an afterthought or a last resort. They are a required element of the analysis that examiners and courts must address whenever the evidence is raised.

The recognized categories

MPEP § 716 identifies the following as accepted categories of objective indicia of non-obviousness:

Commercial success requires hard evidence, not general sales claims. The evidence must show that the product achieved market acceptance in a competitive environment.

Long-felt but unsolved need requires showing that the need was persistent and recognized by those of ordinary skill in the art before the invention addressed it. An unsatisfied need that became apparent only after the invention was announced does not support this category.

Failure of others focuses on competitors who had the opportunity and motivation to solve the same problem but did not succeed. The evidence is strongest when those competitors were active, well-resourced, and working on the same problem.

Unexpected results include synergistic effects, properties not found in prior art compounds or combinations, and the presence of characteristics that skilled artisans would not have predicted from the prior art. Comparative testing against the closest prior art is the typical vehicle for establishing this category.

Skepticism of experts carries particular weight. Expressions of disbelief by experts skilled in the art constitute strong evidence of non-obviousness, because the experts' own pre-invention assessments belie any claim that the result was routine or predictable. Contemporaneous skepticism is more probative than reconstructed post-hoc doubts.

Copying by competitors is relevant because a rational competitor who believed the invention was obvious would design around it rather than reproduce it. Evidence of copying is strongest when the competitor had access to the patent claims and chose to copy rather than invent around.

Industry praise from those skilled in the art supports non-obviousness for the same reason as expert skepticism: people working in the field are affirming that the achievement was non-trivial.

Licensing activity can indicate non-obviousness when competitors take licenses rather than design around or challenge the patent, though examiners evaluate whether licensing occurred for reasons unrelated to the claimed invention's merit.

The nexus requirement

Evidence of secondary considerations receives substantial weight only when it has a factually and legally sufficient connection to the claimed invention, a requirement known as nexus. The applicant bears the burden of establishing this connection.

Nexus is presumed when the applicant demonstrates that the objective evidence is tied to a product that embodies the claimed features and is coextensive with them. When the commercial product incorporates features beyond the claim scope, or when the evidence of success traces back to features already in the prior art, the presumption does not arise and the applicant must affirmatively establish the link through evidence.

A common nexus failure is commercial success driven by marketing, brand recognition, or features that were already in the prior art. That success does not trace back to what was novel about the claimed invention, so it does not tend to show the invention was non-obvious. The key question is always whether the objective evidence is attributable to what the claims added over the prior art.

How evidence is weighed

Secondary considerations are not automatically dispositive. The mere fact that an applicant has presented evidence does not mean the evidence is dispositive of the issue of obviousness, and the evidence must be weighed against the full record, including the strength of the prima facie case. A very strong prima facie case, where the prior art combination closely maps onto the claims with a clear motivation to combine, can outweigh secondary considerations evidence.

When the applicant submits objective evidence, the examiner or tribunal must reweigh all evidence rather than simply evaluate whether the secondary considerations are individually sufficient to knock down the prima facie case. This means the initial obviousness determination is not treated as fixed; the full record is reconsidered in light of everything presented.

Critically, arguments alone cannot substitute for evidence. When relying on secondary considerations to traverse an obviousness rejection, the applicant must present actual evidence, such as sales data, declarations from qualified persons, or comparative test results, not mere attorney argument.

Submitting evidence during prosecution

Evidence of secondary considerations may be included in the specification as filed, accompany the application on filing, or be submitted in a timely manner at some point during prosecution. Submitting evidence early, before a final rejection, gives the examiner a complete record to consider before closing prosecution and avoids procedural complications that arise with later-filed evidence.

Affidavits and declarations under 37 C.F.R. § 1.132 are the standard mechanism for introducing secondary considerations evidence to traverse an obviousness rejection. These submissions allow an inventor, industry expert, or other qualified person to attest under oath to facts relevant to non-obviousness, such as the state of the art at the time of the invention, the nature of the commercial success, or the reactions of skilled artisans.

Practical notes for practitioners

• Build the record contemporaneously. Document commercial performance, licensing inquiries, expert reactions, and competitor behavior as they occur. Reconstruction after the fact is harder to credit and harder to make scope-commensurate with the claim.
• Establish nexus before submitting evidence. Identify which features of the commercial product or result are unique to the claimed invention and not present in the prior art. Evidence tied to prior-art features will not advance the non-obviousness argument regardless of how strong the underlying data are.
• Match evidence scope to claim scope. Evidence of unexpected results for one embodiment may not support a broad genus claim if skilled artisans cannot reasonably extrapolate the finding across the full claim scope. Narrow the claim to the supported scope or provide additional data covering the breadth.
• Treat contemporaneous expert skepticism as a strategic asset. Pre-filing opinions that the approach would not work are valuable. Preserve them in writing and consider introducing them through a § 1.132 declaration. Post-hoc reconstructed doubts carry less weight than real-time reactions.
• Secondary considerations in post-grant and litigation. The same Graham framework governs both district court obviousness analysis and obviousness challenges in inter partes review before the Patent Trial and Appeal Board. Evidence gathered during prosecution can be deployed in these forums, making thorough documentation at the prosecution stage valuable long after allowance.
• Consider a focused claim amendment alongside the evidence. When secondary considerations support a narrower embodiment better than the full claim scope, amending claims to track the evidence can both strengthen the nexus and focus prosecution efficiently.