The Graham Factors: A Step-by-Step Framework for Obviousness Analysis

Key Takeaways

• The four Graham factors — established by the Supreme Court in Graham v. John Deere Co., 383 U.S. 1 (1966) — are the legally mandated framework for every obviousness determination under 35 U.S.C. § 103. They aren’t optional analytical tools; they’re the standard every examiner must apply and every applicant can enforce.
• KSR v. Teleflex (2007) expanded the analysis beyond the rigid Teaching, Suggestion, or Motivation (TSM) test — but it did not give examiners a blank check. The Supreme Court still requires “some articulated reasoning with some rational underpinning” for every prior art combination.
• The examiner bears the initial burden of establishing a prima facie case of obviousness with specific evidence — not conclusory statements, not “common sense” hand-waving, and not hindsight-driven reconstruction of the invention from the applicant’s own disclosure.
• Secondary considerations are not optional tiebreakers. Commercial success, long-felt need, failure of others, and unexpected results are legally mandated evidence that examiners must consider. The Federal Circuit has reversed obviousness findings where the Patent Office failed to weigh this evidence properly.
• Hindsight bias is among the greatest threats to fair patent obviousness analysis — and the Graham framework exists specifically to guard against it. Recognizing the red flags of hindsight reasoning is a core prosecution skill.
• A structured, evidence-based approach transforms obviousness from a subjective judgment call into a winnable evidentiary argument. This framework is your repeatable methodology for turning § 103 rejections into allowances.

What Is Obviousness Under 35 U.S.C. § 103?

You open the Office Action. The examiner has combined three references you’ve never seen cited together — one from a different field entirely — and concluded that your client’s invention would have been “obvious to one of ordinary skill in the art.” The rationale is two sentences long. The reasoning feels backwards, as if the examiner read the patent first and then went looking for pieces in the prior art to reassemble it.

That’s a § 103 rejection. And it’s beatable — if you know the framework.

Obviousness under 35 U.S.C. § 103 means that the differences between the claimed invention and the prior art would have been obvious to a hypothetical “person having ordinary skill in the art” (PHOSITA) at the time of filing. The critical word is would — not could. The question isn’t whether a skilled person could have arrived at the invention. It’s whether the prior art made it obvious that they would.

Every obviousness analysis in the United States runs through the same four-factor test, established by the Supreme Court in Graham v. John Deere Co., 383 U.S. 1 (1966). This isn’t a discretionary framework. It’s the legal standard, and examiners are required to apply it:

1. Scope and content of the prior art — What relevant prior art exists in the field?
2. Differences between the prior art and the claimed invention — What specific gaps exist between what’s known and what’s claimed?
3. Level of ordinary skill in the pertinent art — What would a person of ordinary skill in this field know, understand, and be capable of?
4. Secondary considerations (objective indicia of non-obviousness) — What real-world evidence — commercial success, unexpected results, failure of others — supports or undermines an obviousness finding?

Before Graham, obviousness determinations were dangerously subjective. Judges and examiners relied on vague notions of “inventive genius” that led to inconsistent, often unfair outcomes. The Supreme Court recognized the problem: without a structured factual inquiry, it’s too easy to look at a completed invention and conclude, with the benefit of hindsight, that the result was obvious all along. The Graham factors replaced that subjectivity with a disciplined, evidence-based methodology.

Carry this through every § 103 response you draft: obviousness is not a vibes check. It’s a factual inquiry. The facts are yours to develop and present.

The Four Graham Factors: Your Obviousness Analysis Framework

Each factor asks a distinct question and demands its own analytical approach.

Factor	Question It Answers	Key Analytical Focus
1. Scope & Content of Prior Art	What relevant prior art exists?	Defining the field, identifying analogous art, mapping what each reference actually teaches
2. Differences Between Prior Art and Claims	What’s missing from the prior art?	Element-by-element claim comparison, identifying gaps the examiner must bridge
3. Level of Ordinary Skill (PHOSITA)	Who is the hypothetical skilled person?	Education, experience, knowledge boundaries — the PHOSITA is ordinary, not omniscient
4. Secondary Considerations	What does the real-world evidence show?	Commercial success, long-felt need, failure of others, unexpected results, teaching away, skepticism

The first three factors frame the legal question. The fourth brings in real-world evidence that can tip the balance — and it’s the factor applicants most consistently underutilize.

Why Obviousness Is the Most Common — and Most Misunderstood — Patent Rejection

Section 103 rejections are the most frequently issued grounds for patent rejection at the USPTO. If you’ve filed a patent application, you’ll almost certainly face one.

Here’s where the confusion hits, particularly for founders and inventors encountering the patent system for the first time: an invention can be completely novel — nothing exactly like it exists anywhere in the prior art — and still be rejected as obvious. Novelty under 35 U.S.C. § 102 and obviousness under § 103 are distinct inquiries. Section 102 asks whether the exact invention already exists. Section 103 asks whether the differences between the invention and what exists would have been obvious to a skilled person. You can clear the novelty bar and still stumble on obviousness. (For a deeper look at how novelty analysis works, see novelty requirements under 35 U.S.C. § 102.)

Receiving an obviousness rejection can feel personal — like the examiner is reducing months or years of your work to “anyone could have done that.” That frustration is understandable, and sometimes justified. But the rejection is a legal standard, applied through a specific framework, with evidentiary requirements the examiner must satisfy. It can be challenged. It can be defeated. The framework for doing both is what follows.

Legal Foundations: From Graham v. John Deere to KSR v. Teleflex

The Graham factors don’t exist in a vacuum. Two Supreme Court decisions define how obviousness analysis works in practice — and understanding both is essential to building arguments that hold up.

Graham v. John Deere Co. (1966): Origin of the Four-Factor Test

The case that built the modern obviousness framework started with a plow shank clamp. Graham v. John Deere Co., 383 U.S. 1 (1966), reached the Supreme Court on the question of whether a patent for an improved spring clamp for vibrating plow shanks was obvious over the prior art.

The Court’s holding went far beyond agricultural equipment. Justice Clark, writing for the majority, established that obviousness under § 103 is a question of law based on underlying factual inquiries — and those factual inquiries are the four Graham factors. The Court was explicit about why this structure matters: it guards against the “temptation to read into the prior art the teachings of the invention in issue” and to “substitute hindsight for the statute’s requirement of non-obviousness.”

The practitioner takeaway is foundational: because obviousness is a legal conclusion resting on factual findings, the facts you present — about the prior art’s scope, the differences between references and claims, the PHOSITA’s actual skill level, and the objective evidence of non-obviousness — are not background material. They are the argument. A well-developed factual record can make a legal conclusion of non-obviousness almost inescapable.

KSR International Co. v. Teleflex Inc. (2007): Expanding the Obviousness Standard

For decades after Graham, the Federal Circuit developed what became known as the Teaching, Suggestion, or Motivation (TSM) test. To combine multiple prior art references in a rejection, an examiner had to point to an explicit teaching, suggestion, or motivation in the prior art itself (or in the general knowledge of a PHOSITA) for making that combination. The TSM test gave applicants a powerful shield: no explicit suggestion in the references, no valid combination.

KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), changed the calculus. The Supreme Court rejected the Federal Circuit’s rigid application of the TSM test as the exclusive framework for evaluating prior art combinations. Obviousness analysis, the Court held, must be flexible — allowing examiners to consider common sense, market forces, design incentives, and the known interchangeability of elements.

But KSR didn’t hand examiners a blank check — and this is where many examiners overreach. The Court did not eliminate the requirement for articulated reasoning. It did not grant unlimited discretion to combine references at will. The opinion is explicit: examiners must still supply “some articulated reasoning with some rational underpinning” to support the conclusion that a skilled artisan would have combined the references. Conclusory statements remain insufficient after KSR, just as they were before.

Element	Pre-KSR (Rigid TSM)	Post-KSR (Flexible Analysis)
Rationale for combining references	Required explicit teaching, suggestion, or motivation in the prior art itself	Permits broader reasoning, including common sense, market forces, and design incentives
Examiner flexibility	Limited — needed specific textual support in references	Expanded — but still requires articulated reasoning with rational underpinning
Applicant defense strategy	Challenge the absence of TSM in the references	Challenge the quality and specificity of the examiner’s rationale
Burden of proof	Examiner must show explicit motivation	Examiner must still articulate why a PHOSITA would combine — with more flexibility in sourcing that reasoning

The practical shift: you can no longer rely solely on “there’s no TSM in the references” as your primary argument. Instead, scrutinize the quality of the examiner’s reasoning. Is their rationale specific to the references at hand, or is it generic boilerplate that could apply to any combination? Do they explain why a PHOSITA would have been motivated to combine these particular references to solve this particular problem? If not, the rejection is vulnerable.

What the Statute Actually Says: 35 U.S.C. § 103

The statute itself is deceptively short. Section 103 provides that 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.”

Every phrase in that sentence does analytical work:

• “The claimed invention as a whole” — The examiner must evaluate the full claim, not cherry-pick individual elements. A dissection that ignores how the elements interact as a combination is legally improper.
• “Would have been obvious” — Not could have been. This is the reasonable expectation standard, not a possibility test.
• “Before the effective filing date” — Under the America Invents Act (AIA), the prior art universe is fixed as of the filing date (or priority date). Anything published or publicly available before that date is fair game; anything after is not.
• “Person having ordinary skill in the art” — The PHOSITA is a legal construct, not a real person. Defining this hypothetical person’s knowledge, education, and capabilities is a factual determination that shapes the entire analysis.

The burden of proof rests initially with the USPTO. Under MPEP § 2142, the examiner must establish a prima facie case of obviousness — sufficient evidence and reasoning that, if unrebutted, would support a conclusion of obviousness. Only then does the burden shift to the applicant. This allocation matters enormously: if the examiner’s prima facie case is deficient, you can challenge it on that basis alone, before you even reach the merits.

Applying the Graham Factors: A Step-by-Step Methodology

This is the operational heart of the framework — where each Graham factor gets a detailed treatment: what it means, how to analyze it, and how to argue it. Keep this as the playbook you return to every time you crack open a § 103 Office Action.

Factor 1: Scope and Content of the Prior Art

The first Graham factor asks a deceptively simple question: what prior art actually matters here?

What it means: You’re defining the universe of knowledge a PHOSITA would have known about and considered relevant at the time of filing. Not everything ever published — only art that falls within the field of the invention or is reasonably pertinent to the problem the inventor was solving.

How to analyze it: The key tool in this prior art analysis is the analogous art doctrine. Under MPEP § 2141.01(a), a prior art reference qualifies as analogous art if it meets either of two tests:

1. Same field of endeavor — Is the reference from the same technical field as the claimed invention?
2. Reasonably pertinent to the problem — Even if from a different field, is the reference reasonably pertinent to the particular problem the inventor was trying to solve?

If a reference fails both tests, it is non-analogous art and cannot properly support an obviousness rejection. This is a threshold question many practitioners overlook — but it can be dispositive. One successful analogous art challenge and the entire rejection collapses.

How to argue it: When reviewing a § 103 rejection, start with the prior art itself:

• Is each cited reference truly analogous? Would a person working in your inventor’s field actually have encountered it or thought to look for it?
• Has the examiner defined the field too broadly? An examiner who characterizes a specialized biomedical device as falling within the general field of “mechanical engineering” has artificially expanded the prior art universe to find references they need.
• Conversely, has the examiner defined the field too narrowly, excluding art that would show the true state of knowledge more accurately?
• Does each reference actually teach what the examiner claims it teaches? Read the references yourself — examiner characterizations are sometimes broader than what the reference actually supports.

Decision Framework — Is the Cited Reference Analogous Art?

→ Is it from the same field of endeavor as the claimed invention?

• Yes → Analogous art. Proceed to Factor 2 analysis.
• No → Is it reasonably pertinent to the problem the inventor was trying to solve?
  • Yes → Analogous art. Proceed to Factor 2 analysis.
  • No → Non-analogous art. Challenge the examiner’s use of this reference.

Factor 2: Identifying Differences Between Prior Art and Claims

This is where the analysis gets granular. Factor 2 demands a precise, element-by-element comparison between what the prior art discloses and what the claims actually recite.

What it means: You’re mapping every limitation in the claims against the cited prior art to find exactly where the gaps are. If the examiner says Reference A teaches limitation X, you need to verify that the reference actually discloses that limitation, in the context the examiner asserts, with enough detail to satisfy the claim language. No impressionism — specificity.

How to analyze it: Build a claim chart. For each independent claim, list every limitation in one column. In adjacent columns, identify which reference the examiner relies on for each limitation and note the specific passage cited. Then assess: which limitations are fully met by a single reference, which require combining multiple references, and which are absent entirely — or present only through an unreasonable reading?

Claim Limitation	Reference A	Reference B	Reference C	Status
Element 1: [description]	Disclosed at col. 4, ll. 15-22	—	—	Met
Element 2: [description]	—	Partially disclosed at ¶ [0034]	—	Gap: requires inference
Element 3: [description]	—	—	—	Missing from all cited art
Element 4: [description]	Disclosed at col. 7, ll. 3-10	Disclosed at ¶ [0051]	—	Met (but requires combination)

How to argue it: The claim chart is your primary weapon. Emphasize limitations that are absent or only loosely suggested. Where the examiner bridges a gap through combination, challenge the bridge: does the combination actually account for the missing limitation, or has the examiner filled the gap with an assumption? Each combination point is a potential vulnerability — the examiner must justify each one with specific reasoning, not just the overall conclusion.

Watch for a particular red flag: when the examiner’s characterization of what a reference “teaches” or “suggests” goes beyond what the reference actually says. This is where many weak obviousness rejections live. Read the cited passages yourself. If the examiner is interpolating — finding teachings between the lines that the reference doesn’t explicitly state — that’s an argument waiting to be made.

Factor 3: Defining the Person of Ordinary Skill (PHOSITA)

The PHOSITA is the measuring stick for the entire obviousness analysis. Get this definition wrong, and the whole framework skews.

What it means: The “person having ordinary skill in the art” is a legal fiction — a hypothetical construct used to establish the baseline of knowledge and capability against which the invention is measured. This person is neither a novice nor a genius. They possess ordinary skill: the knowledge and experience typical of practitioners in the relevant field.

How to define PHOSITA: Under MPEP § 2141.03, relevant factors include:

• Education level typical of workers in the field
• Type and scope of problems encountered in the art
• Prior art solutions to those problems
• Rapidity with which innovations are made
• Sophistication of the technology

The PHOSITA is a composite that varies by technology. In a software patent, ordinary skill might mean a developer with a bachelor’s degree and three to five years of relevant experience. In a pharmaceutical patent, it might mean a medicinal chemist with a Ph.D. and familiarity with the specific therapeutic area. The definition matters because the PHOSITA’s assumed knowledge directly determines what combinations or modifications count as “obvious.”

How to argue it: Examiners sometimes inflate the PHOSITA — quietly assuming a hypothetical person with knowledge and capabilities that go well beyond “ordinary.” If the examiner’s combination requires sophisticated cross-disciplinary knowledge, creative leaps, or insight into the specific problem the inventor solved, challenge the PHOSITA definition directly. The PHOSITA doesn’t have the inventor’s hindsight. They don’t routinely combine unrelated fields. They don’t possess exceptional creativity. That’s the entire point of the word ordinary: if it took an inventor’s insight to arrive at the claimed invention, the invention isn’t obvious to a person of ordinary skill.

One of the most effective prosecution arguments is showing that the examiner’s rationale implicitly requires a PHOSITA who is more skilled than “ordinary.” If the combination only makes sense to someone with the inventor’s specific insight, the examiner has measured against the wrong person.

Factor 4: Secondary Considerations as Evidence of Non-Obviousness

This is one of the most underutilized tools in patent prosecution — and often one of the most powerful.

Secondary considerations, also called “objective indicia of non-obviousness,” are real-world evidence bearing on whether an invention was truly obvious. The Supreme Court in Graham identified them as part of the analysis, and the Federal Circuit has repeatedly reinforced that they are not optional extras or last-resort arguments. In Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530 (Fed. Cir. 1983), the court was emphatic: evidence of secondary considerations “must always when present be considered” and may be “the most probative and cogent evidence” in the obviousness analysis.

Absorb that language. “Must always when present be considered.” If you present secondary considerations and the examiner ignores them or gives them only cursory treatment, the rejection is procedurally deficient.

Here are the recognized categories:

• Commercial success. Significant sales, market share, or licensing revenue attributable to the claimed invention tells the market’s story: if the invention were truly obvious, someone would have already done it. The key is attribution — you need financial data tied to the claimed features, not just the product generally.
• Long-felt but unsolved need. A problem that persisted for years while the industry failed to solve it suggests the solution wasn’t obvious. This argument hits hardest in crowded fields where many skilled practitioners were aware of the problem and actively working on it.
• Failure of others. Documented attempts by competitors or researchers that didn’t succeed. If skilled people tried and failed, the solution wasn’t obvious to a person of ordinary skill. The evidence trail matters — you need specifics, not generalizations.
• Unexpected results. Performance that a PHOSITA would not have predicted — results that are better, different, or surprising relative to what the prior art would suggest. Especially valuable in chemical and pharmaceutical cases, where small structural changes can produce dramatically different effects.
• Industry skepticism and teaching away. Prior art that actively discouraged the approach the inventor took — or experts who were skeptical it would work. Art that “teaches away” from the claimed combination is one of the strongest arguments against obviousness, because it shows the prior art itself pointed away from the solution, not toward it.
• Copying by competitors. Competitors who copied the patented invention rather than designing around it. If the invention were merely an obvious variation, competitors would design their own versions. Copying implies the invention offered something they couldn’t easily replicate through routine skill.
• Industry praise and recognition. Awards, publications, or expert acknowledgment of the invention’s significance.

Secondary Consideration	Persuasive Weight	Ease of Documentation	Common Examiner Challenge
Commercial Success	High	Moderate — requires financial data tied to claimed features	“Success is due to marketing, not the invention”
Long-Felt Need	High	Moderate — requires showing timeline and industry awareness	“The need wasn’t truly unmet — alternatives existed”
Failure of Others	Very High	Difficult — requires documenting competitors’ specific attempts	“Different approaches, different problem”
Unexpected Results	Very High	Moderate — requires comparative test data	“Results are merely better, not unexpected”
Teaching Away	Very High	Moderate — requires identifying specific prior art passages	“The reference doesn’t explicitly discourage the combination”
Copying	Moderate	Difficult — requires evidence of competitors’ knowledge and behavior	“Copying was for other reasons (cost, convenience)”
Industry Praise	Moderate	Easy — awards, publications, expert statements	“Praise is for the product, not the claimed features”

The Nexus Requirement: Connecting Secondary Evidence to Patent Claims

Secondary considerations can make or break an obviousness response. But they come with a prerequisite that trips up even experienced practitioners — and when that prerequisite is missing, the evidence loses its teeth.

What “Nexus” Means and Why It Matters

To rely on secondary considerations, you must establish a nexus — a legally sufficient connection between the non-obviousness evidence and the specific features of the claimed invention. The commercial success, unexpected results, or other evidence must be attributable to the novel aspects of the claims — not to unclaimed features, prior art elements, marketing spend, or factors unrelated to the patent.

The Federal Circuit has drawn this line clearly. In Ormco Corp. v. Align Technology, Inc., 463 F.3d 1299 (Fed. Cir. 2006), the court explained that the nexus must link secondary considerations to what is “novel in the claim, not the invention as a whole” when the product has both novel and conventional elements. And in In re Huang, 100 F.3d 135 (Fed. Cir. 1996), the court reinforced that without a nexus, secondary considerations evidence — however impressive — carries little weight.

The logic is straightforward: if your product is selling well, but the success is driven by brand reputation, pricing, or a feature that already existed in the prior art, that success doesn’t tell us anything about whether the claimed invention was obvious. Nexus ensures the evidence actually answers the legal question.

How to Establish and Defend Nexus in Practice

Building a strong nexus requires specificity and planning — ideally starting before prosecution, not after a rejection lands on your desk.

Tie evidence to claimed features, not the product. If you’re relying on commercial success, isolate the revenue or adoption attributable to the claimed features specifically. Feature-level data is far more persuasive than product-level data. If your patent claims a specific mechanism within a larger device, show that customers are choosing the product because of that mechanism.

Use controlled comparisons. A/B testing, comparative performance data, or before-and-after metrics that isolate the claimed features’ contribution are extremely effective. If the product performed significantly better after incorporating the claimed invention, with other variables controlled, that’s a strong nexus.

Obtain expert declarations. Declarations under 37 CFR 1.132 from industry experts who can articulate the causal connection between the secondary consideration and the claimed features add significant weight. The expert should explain why the link exists — not just assert it.

Anticipate the challenges. The examiner’s attacks on nexus are predictable:

• “Commercial success is due to marketing, not the invention.” → Counter with evidence isolating the technical contribution: customer surveys focused on functional features, sales data showing adoption driven by technical performance, or evidence that marketing highlighted the claimed feature as the key differentiator.
• “The entire product is successful, not just the claimed feature.” → Counter with feature-specific data, evidence that the claimed feature is the primary driver of adoption, or a showing that the product without the claimed feature failed or performed significantly worse.

Defeating Hindsight Bias in Patent Obviousness Rejections

Every element of obviousness analysis circles back to one danger: hindsight bias. It is the most common way § 103 analysis goes wrong, and the Graham framework exists specifically to combat it.

What Hindsight Bias Looks Like in Examiner Rejections

Picture the process in reverse. The examiner reads your patent application. They see the problem, the solution, and exactly how the pieces fit together. Then they search the prior art — already knowing the answer — and find references that contain pieces of the puzzle. They arrange those pieces in the order the inventor arranged them and conclude: obvious.

That’s hindsight bias. The Supreme Court warned against it directly in Graham: it is impermissible to use the patent in suit as a guide through the maze of prior art, finding and assembling the claimed combination after the fact.

The danger is cognitive and pervasive. Once you know the answer, everything looks easier in retrospect. The references that seemed unrelated suddenly appear connected. The combination that required genuine insight now looks like one logical step. Examiners are as susceptible to this as anyone — and the structure of patent examination, where the examiner reviews the invention before searching the prior art, makes it structurally unavoidable without disciplined safeguards.

Watch for these red flags in Office Actions:

The “Hindsight Red Flags” Checklist:

• Conclusory combination statements: “It would have been obvious to combine References A and B” — without explaining why a PHOSITA would have combined these specific references to solve this specific problem.
• Inflated PHOSITA: The examiner describes a skilled person whose capabilities conveniently match what’s needed to make the combination, rather than defining the PHOSITA based on the actual field.
• Cherry-picking from unrelated references: Isolated elements selected from references in disparate fields that a PHOSITA would never have considered together.
• “Common sense” without evidence: Reliance on “common sense” or “routine optimization” without supporting evidence or specific explanation. KSR permits common sense reasoning, but not untethered from the facts.
• The specification as roadmap: The examiner’s combination closely mirrors the structure of the applicant’s own disclosure — suggesting they reverse-engineered the obviousness rationale from the invention itself.
• Vague motivation to combine: “To improve the device” or “to achieve better performance” — motivations so generic they could justify any combination of any references.
• Excessive reference count: Combinations requiring four, five, or more references to cover all claim limitations. Each additional reference makes the combination more suspect.

Strategies to Counter Hindsight Bias in Office Action Responses

Once you’ve spotted the red flags, turn them into arguments.

• Demand articulated reasoning. Even under KSR‘s flexible standard, the examiner must supply “some articulated reasoning with some rational underpinning” for every combination. If the rejection relies on conclusory language, challenge it directly. Quote the KSR standard and point out exactly where the reasoning falls short.
• Attack the motivation to combine. If the references address different problems, operate by different mechanisms, or wouldn’t naturally be considered together by a PHOSITA, argue there was no motivation to combine. This is particularly effective when the references come from different technical fields or when combining them would destroy the intended function of one reference. The “teaching away” doctrine is your ally here. If one reference actually discourages the approach the examiner proposes — explicitly or by implication — the combination is improper. A PHOSITA is presumed to consider the entirety of each reference, including its warnings and limitations, not just the isolated sentences the examiner selected.
• Challenge the number of references. Every additional reference weakens the obviousness case. A two-reference combination might be straightforward. Three references deserve scrutiny. Four or more? Inherently suspect. The more references needed, the less likely a PHOSITA would have assembled them without the inventor’s blueprint as a guide.
• Invoke secondary considerations. This is where Factor 4 becomes strategically essential. Secondary considerations are the legally recognized antidote to hindsight bias. Commercial success, industry failure, expert skepticism — these facts exist in the real world, independent of the patent application. They can’t be explained away by hindsight reconstruction. They are the objective counterweight to the examiner’s subjective reasoning.

The Examiner’s Burden of Proof in Obviousness Determinations

Here’s a fact that changes how many applicants think about § 103 rejections: the examiner carries the initial burden of proof. You don’t have to prove your invention is non-obvious. The examiner must first prove it is obvious — and that burden has specific, enforceable requirements.

The Prima Facie Case: What Examiners Must Establish

A prima facie case of obviousness is the threshold showing the examiner must make before the burden shifts to you. Under MPEP § 2142, establishing it requires the examiner to:

1. Identify each claim limitation in the prior art — across one or more references, show where every element of the claim is disclosed or suggested.
2. Provide a rationale for combining references — if the rejection relies on multiple references, explain why a PHOSITA would have combined them. Post-KSR, this rationale can be broader than the old TSM test required — but it still must be articulated and reference-specific.
3. Explain the expected result — identify why the combination would have produced the claimed invention with a reasonable expectation of success.

If any of these elements is missing or deficient, the prima facie case fails. That’s not a procedural technicality — it’s a substantive deficiency you should assert directly.

Challenging Deficient Examiner Rationales

In practice, prima facie cases fall short in predictable ways:

• Missing or conclusory motivation to combine. The examiner states the combination would have been obvious but offers no specific explanation of why a PHOSITA would have been motivated to make it. Response: cite KSR‘s requirement for “articulated reasoning with rational underpinning” and identify the absence of reference-specific reasoning.
• Failure to account for all claim limitations. An element is simply missing from the rejection, or the examiner glosses over it with a vague statement like “the remaining limitations are well-known in the art.” Response: identify the unaccounted limitation specifically and require the examiner to show where it is taught or suggested.
• Improper reliance on applicant’s own disclosure. The examiner uses teachings from the applicant’s specification — rather than the prior art — to bridge gaps. This is a form of hindsight bias and is legally impermissible. Response: the rejection must stand on the prior art alone.
• Overly broad PHOSITA characterization. The examiner implicitly assumes a PHOSITA with knowledge beyond ordinary skill — for instance, familiarity with multiple unrelated technical fields. Response: define the PHOSITA based on the actual factors in MPEP § 2141.03 and argue that the combination requires more than ordinary skill.

When the prima facie case remains deficient after your response and the examiner maintains the rejection without adequately addressing your arguments, you’ve built a strong record for appeal. Filing declarations or affidavits under 37 CFR 1.132 — with expert testimony supporting your positions — can add significant weight to the rebuttal.

Responding to § 103 Rejections: A Practical Step-by-Step Playbook

Everything above converges here. This is where framework knowledge becomes action — a concrete process for responding to an obviousness rejection. Whether you’re the attorney drafting the response or the founder evaluating your attorney’s work, this is the workflow.

10-Step Framework for Responding to Obviousness Rejections

Step 1: Read the rejection and identify the examiner’s rationale type. Single-reference rejection or multi-reference combination? What is the stated motivation to combine? What MPEP rationale does the examiner cite? The structure of the rejection tells you where the pressure points are.

Step 2: Map every claim limitation against each cited reference. Build your claim chart — element by element. For each limitation, identify the specific passage the examiner cites and assess whether the reference actually teaches what the examiner says it teaches. This is where rejections start to unravel.

Step 3: Evaluate the prior art’s scope. Is each reference truly analogous art? Apply the two-part test from MPEP § 2141.01(a). If a reference fails both prongs, it’s improper — and that alone can be enough to overcome the rejection.

Step 4: Challenge the motivation to combine. Does the examiner provide specific, evidence-based reasoning for why a PHOSITA would have combined these particular references? Or is the rationale generic and conclusory? Demand specificity.

Step 5: Assess the PHOSITA definition. Has the examiner inflated the PHOSITA’s skill level? If the combination requires cross-disciplinary knowledge, creative problem-solving, or the inventor’s specific insight, the PHOSITA has been defined incorrectly.

Step 6: Identify hindsight bias indicators. Review the rejection against the Hindsight Red Flags Checklist. If the examiner’s reasoning tracks the structure of your application rather than flowing naturally from the prior art, hindsight is likely at work.

Step 7: Gather and present secondary considerations. Collect evidence of commercial success, unexpected results, failure of others, long-felt need, teaching away, or industry skepticism. Establish nexus to the claimed features. Present this as affirmative evidence — not an afterthought.

Step 8: Draft the response. Lead with your strongest arguments. Address each of the examiner’s points specifically — generalized arguments that don’t engage with the rejection’s actual reasoning are wasted ink. Present secondary considerations as affirmative evidence of non-obviousness, not a fallback position. For strategies on structuring effective Office Action responses, contact us for patent defense strategies.

Step 9: Consider an examiner interview. A pre-response or post-response interview can be remarkably effective. It lets you gauge the examiner’s actual concerns (which sometimes differ from what’s written), present arguments directly, and narrow the issues before committing to a formal written response.

Step 10: Preserve the record for appeal. If the rejection is maintained, ensure all arguments and evidence are in the prosecution history for PTAB review. Arguments not raised during prosecution are generally waived on appeal. Build the record as if it will be read by a PTAB judge — because it might be.

When to Request an Examiner Interview

Examiner interviews are among the most underutilized tools in patent prosecution. They work best when the rejection turns on a close factual question where direct dialogue could shift the examiner’s understanding. Common scenarios: the examiner has mischaracterized what a reference teaches, secondary considerations are easier to present in conversation than on paper, or you’re considering claim amendments and want to gauge the examiner’s reaction before narrowing your scope.

Come prepared. Bring a focused agenda with specific proposed arguments or amendments. The goal is to understand the examiner’s position and find common ground — not to deliver a monologue.

Navigating a complex § 103 rejection? An experienced patent attorney can identify the strongest counterarguments and build an evidence-based response. Contact our team for a strategic consultation.

Proactive Strategies: Building Obviousness Defenses Before Prosecution

The best time to prepare for an obviousness rejection is before you ever receive one.

Drafting Claims That Resist Obviousness Rejections

Claim drafting is your first line of defense against § 103 rejections — and a core element of any effective patent prosecution strategy.

• Include specific, narrow limitations. Claims with precise structural or functional limitations are harder to map to the prior art. The more specific the claim language, the more references the examiner needs to piece together — and the weaker their case becomes with each additional reference.
• Use dependent claims strategically. Dependent claims that capture specific performance improvements, particular configurations, or unexpected results give you fallback positions and create additional opportunities to argue secondary considerations. Think of them as pre-built rebuttal platforms.
• Document the inventive process. Lab notebooks, records of failed approaches, competitor analysis, and development timelines create the evidentiary foundation for secondary considerations arguments later. This isn’t just good science — it’s good patent strategy. Every experiment you document now is a fact you can present during prosecution.

Building a Secondary Considerations File From Day One

Don’t wait for a rejection to start gathering evidence. Advise R&D teams and inventors to document the following from the earliest stages of development:

Secondary Considerations Documentation Checklist:

• Commercial success metrics — Track sales data, market share, and licensing revenue attributable to the inventive feature. Isolate the invention’s contribution from general product success where possible.
• Industry recognition — Collect awards, publications, conference presentations, or expert statements recognizing the innovation’s significance.
• Competitor behavior — Document whether competitors have copied the invention, attempted to design around it, or licensed it. Preserve evidence of competitor awareness.
• Failed attempts — Record your own failed approaches and, where available, document competitors’ or academic researchers’ unsuccessful attempts to solve the same problem.
• Unexpected results — Preserve comparative test data showing results that differ from prior art predictions — particularly performance improvements, synergistic effects, or counterintuitive outcomes.
• Industry skepticism — Save communications, publications, or expert opinions expressing doubt that the approach would work.
• Timeline evidence — Document how long the problem existed in the industry before your invention solved it. The longer the gap, the stronger the long-felt need argument.

This transforms secondary considerations from a scramble-after-rejection exercise into a prepared defense that’s ready when you need it.

Want to build obviousness defenses into your patent strategy from the start? Schedule a consultation with our prosecution team.

Common Mistakes in Obviousness Arguments (and How to Avoid Them)

Even experienced practitioners fall into patterns that weaken their responses. These are the mistakes that cost applicants the most.

1. Ignoring secondary considerations entirely. Among the most common and costly errors in obviousness practice. Many practitioners treat secondary considerations as a Hail Mary rather than an integral part of the analysis. The Federal Circuit has been clear: this evidence must be considered. If you have it and don’t present it, you’ve left your strongest argument on the table.
2. Failing to challenge the PHOSITA definition. Accepting the examiner’s implicit PHOSITA without scrutiny means accepting the framework within which the examiner’s combination makes sense. If the combination requires more than ordinary skill, challenge the foundation — don’t just attack the superstructure.
3. Taking the examiner’s word on the prior art. Read the references yourself. Examiner descriptions of what a reference “teaches” can be broader than what the reference supports, more specific than the reference warrants, or focused on a different aspect entirely. A § 103 rebuttal built on the examiner’s characterizations starts from a position of weakness.
4. Presenting secondary considerations without nexus. Impressive commercial success data that isn’t tied to the claimed features carries little weight — and may undermine your credibility if the examiner perceives it as misdirection.
5. Responding to the conclusion rather than the reasoning. “The invention is not obvious because it is innovative” is not a rebuttal. Effective responses attack the examiner’s reasoning point by point: the specific motivation to combine, the specific characterization of each reference, the specific gap in the claim mapping.
6. Waiting until appeal to raise arguments that belong in prosecution. The PTAB reviews the prosecution record. Arguments and evidence not raised before the examiner are generally unavailable on appeal. Build the complete record during prosecution, even if you anticipate an appeal.

Why Obviousness Analysis Matters for Innovation

The obviousness standard under § 103 serves a purpose beyond any single patent application. It’s how the patent system balances two competing imperatives: preventing trivial patents from issuing while ensuring genuine innovation receives meaningful protection.

Protecting Innovation Through Rigorous Legal Standards

A well-applied Graham analysis benefits everyone in the patent ecosystem. Innovators gain confidence that their work will be evaluated against objective criteria rather than subjective impressions. Examiners are held to a discipline that guards against hindsight. And the public gets assurance that issued patents represent real contributions — inventions a person of ordinary skill would not have found obvious.

When the system works, the framework is protective, not punitive. An obviousness rejection isn’t a verdict on the quality of your innovation — it’s a legal determination you can challenge with evidence and argument. The applicants who succeed are those who understand the framework and engage with it systematically.

The Evolving Landscape: AI, Examiner Guidance, and Future Developments

The Graham framework is nearly sixty years old. Its core structure remains remarkably stable. The context around it does not.

• AI-assisted prior art searches are expanding the scope and efficiency of what examiners can find and cite. As these tools improve, applicants should expect more comprehensive prior art rejections — and should prepare by conducting thorough pre-filing searches of their own.
• The PTAB’s growing body of decisions continues to refine how the Graham factors are applied in practice, particularly around secondary considerations, nexus requirements, and the permissible scope of examiner reasoning post-KSR.
• Emerging guidance on AI-generated inventions raises questions about how the PHOSITA standard applies when the “person” of ordinary skill might be assisted by — or replaced by — artificial intelligence in the inventive process.

The fundamentals, though, are constant. Practitioners who master the Graham factors, understand the evidentiary requirements, and build disciplined prosecution strategies around the four-factor framework will be positioned to adapt regardless of how the tools and landscape shift around them.

Your Framework for Defeating Obviousness Rejections

The Graham factors transform obviousness from a subjective judgment call into a structured factual inquiry you can win. The scope of prior art defines the battlefield. The differences between prior art and claims reveal where the examiner must prove their case. The PHOSITA definition sets the measuring stick. And secondary considerations bring real-world evidence that can outweigh even a facially strong prima facie case.

Pair this framework with disciplined hindsight-bias detection, a clear understanding of the examiner’s burden, and proactive evidence documentation — and you have a complete methodology for turning § 103 rejections into allowances.

An obviousness rejection is not the end of your patent. It’s the beginning of an evidentiary argument. With the right framework, it’s one you can win.

If you’re facing a § 103 rejection or want to build obviousness-proof patent applications from the start, contact Amir Adibi for a strategic consultation.