MPEP 2141
Examination Guidelines for Determining Obviousness Under

This is the Ninth Edition of the MPEP, Revision 07.2015, Last Revised in November 2015

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2141    Examination Guidelines for Determining Obviousness Under 35 U.S.C. 103 [R-07.2015]

[Editor Note: This MPEP section is applicable to applications subject to the first inventor to file (FITF) provisions of the AIA except that the relevant date is the "effective filing date" of the claimed invention instead of the "time of the invention," which is only applicable to applications subject to pre-AIA 35 U.S.C. 102. See 35 U.S.C. 100 (note) and MPEP § 2150 et seq.]

35 U.S.C. 103   Conditions for patentability; non-obvious subject matter

A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, 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. Patentability shall not be negated by the manner in which the invention was made.

Pre-AIA 35 U.S.C. 103   Conditions for patentability; nonobvious subject matter

  • (a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.

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EXAMINATION GUIDELINES FOR DETERMINING OBVIOUSNESS UNDER 35 U.S.C. 103

These guidelines are intended to assist Office personnel to make a proper determination of obviousness under 35 U.S.C. 103, and to provide an appropriate supporting rationale in view of the recent decision by the Supreme Court in KSR International Co. v. Teleflex Inc. (KSR), 550 U.S. 398, 82 USPQ2d 1385 (2007). The guidelines are based on the Office’s current understanding of the law, and are believed to be fully consistent with the binding precedent of the Supreme Court. The KSR decision reinforced earlier decisions that validated a more flexible approach to providing reasons for obviousness. However, the Supreme Court’s pronouncement in KSR overruled cases such as In re Lee, 277 F.3d 1338, 61 USPQ2d 1430 (Fed. Cir. 2002), insofar as those cases require record evidence of an express reason to modify the prior art. As the Federal Circuit has explained:

At the time [of the decision in In re Lee], we required the PTO to identify record evidence of a teaching, suggestion, or motivation to combine references because “[o]mission of a relevant factor required by precedent is both legal error and arbitrary agency action.” However, this did not preclude examiners from employing common sense. More recently [in DyStar Textilfarben GmbH v. C.H. Patrick Co., 464 F.3d 1356, 1366 (Fed.Cir. 2006)], we explained that use of common sense does not require a “specific hint or suggestion in a particular reference,” only a reasoned explanation that avoids conclusory generalizations.

Perfect Web Technologies, Inc. v. InfoUSA, Inc., 587 F.3d 1324, 1329, 92 USPQ2d 1849, 1854 (Fed. Cir. 2009) (citations omitted).

These guidelines do not constitute substantive rule making and hence do not have the force and effect of law. They have been developed as a matter of internal Office management and are not intended to create any right or benefit, substantive or procedural, enforceable by any party against the Office. Rejections will continue to be based upon the substantive law, and it is these rejections that are appealable. Consequently, any failure by Office personnel to follow the guidelines is neither appealable nor petitionable.

I. THE KSR DECISION AND PRINCIPLES OF THE LAW OF OBVIOUSNESS

The Supreme Court in KSR reaffirmed the familiar framework for determining obviousness as set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), but stated that the Federal Circuit had erred by applying the teaching-suggestion-motivation (TSM) test in an overly rigid and formalistic way. KSR, 550 U.S. at 404, 82 USPQ2d at 1391. Specifically, the Supreme Court stated that the Federal Circuit had erred in four ways: (1) “by holding that courts and patent examiners should look only to the problem the patentee was trying to solve ” (Id. at 420, 82 USPQ2d at 1397); (2) by assuming “that a person of ordinary skill attempting to solve a problem will be led only to those elements of prior art designed to solve the same problem” (Id.); (3) by concluding “that a patent claim cannot be proved obvious merely by showing that the combination of elements was ‘obvious to try’” (Id. at 421, USPQ2d at 1397); and (4) by overemphasizing “the risk of courts and patent examiners falling prey to hindsight bias” and as a result applying “[r]igid preventative rules that deny factfinders recourse to common sense” (Id.).

In KSR, the Supreme Court particularly emphasized “the need for caution in granting a patent based on the combination of elements found in the prior art,”Id. at 415, 82 USPQ2d at 1395, and discussed circumstances in which a patent might be determined to be obvious. Importantly, the Supreme Court reaffirmed principles based on its precedent that “[t]he combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.”Id. at 415-16, 82 USPQ2d at 1395. The Supreme Court stated that there are “[t]hree cases decided after Graham [that] illustrate this doctrine.” Id. at 416, 82 USPQ2d at 1395. (1) “In United States v. Adams,.. . [t]he Court recognized that when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” Id. (2) “In Anderson’s-Black Rock, Inc. v. Pavement Salvage Co.,.. . [t]he two [pre-existing elements] in combination did no more than they would in separate, sequential operation.” Id. at 416-17, 82 USPQ2d at 1395. (3) “[I]n Sakraida v. AG Pro, Inc., the Court derived. .. the conclusion that when a patent simply arranges old elements with each performing the same function it had been known to perform and yields no more than one would expect from such an arrangement, the combination is obvious.” Id. at 417, 82 USPQ2d at 1395-96 (Internal quotations omitted.). The principles underlining these cases are instructive when the question is whether a patent application claiming the combination of elements of prior art would have been obvious. The Supreme Court further stated that:

When a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one. If a person of ordinary skill can implement a predictable variation, § 1.3 likely bars its patentability. For the same reason, if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill. Id. at 417, 82 USPQ2d at 1396.

When considering obviousness of a combination of known elements, the operative question is thus “whether the improvement is more than the predictable use of prior art elements according to their established functions.” Id.

The Supreme Court’s flexible approach to the obviousness inquiry is reflected in numerous pre-KSR decisions; see MPEP § 2144. That section provides many lines of reasoning to support a determination of obviousness based upon earlier legal precedent that had condoned the use of particular examples of what may be considered common sense or ordinary routine practice (e.g., making integral, changes in shape, making adjustable). Thus, the type of reasoning sanctioned by the opinion in KSR has long been part of the patent examination process.

II. THE BASIC FACTUAL INQUIRES OF GRAHAM v. JOHN DEERE CO.

An invention that would have been obvious to a person of ordinary skill at the time of the invention is not patentable. See 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a). As reiterated by the Supreme Court in KSR, the framework for the objective analysis for determining obviousness under 35 U.S.C. 103 is stated in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966). Obviousness is a question of law based on underlying factual inquiries. The factual inquiries enunciated by the Court are as follows:

  • (A) Determining the scope and content of the prior art; and
  • (B) Ascertaining the differences between the claimed invention and the prior art; and
  • (C) Resolving the level of ordinary skill in the pertinent art.

Objective evidence relevant to the issue of obviousness must be evaluated by Office personnel. Id. at 17-18, 148 USPQ at 467. Such evidence, sometimes referred to as “secondary considerations,” may include evidence of commercial success, long-felt but unsolved needs, failure of others, and unexpected results. The evidence may be included in the specification as filed, accompany the application on filing, or be provided in a timely manner at some other point during the prosecution. The weight to be given any objective evidence is made on a case-by-case basis. The mere fact that an applicant has presented evidence does not mean that the evidence is dispositive of the issue of obviousness.

The question of obviousness must be resolved on the basis of the factual inquiries set forth above. While each case is different and must be decided on its own facts, the Graham factors, including secondary considerations when present, are the controlling inquiries in any obviousness analysis. The Graham factors were reaffirmed and relied upon by the Supreme Court in its consideration and determination of obviousness in the fact situation presented in KSR, 550 U.S. at 406-07, 82 USPQ2d at 1391 (2007). The Supreme Court has utilized the Graham factors in each of its obviousness decisions since Graham. See Sakraida v. Ag Pro, Inc., 425 U.S. 273, 189 USPQ 449, reh’g denied, 426 U.S. 955 (1976); Dann v. Johnston, 425 U.S. 219, 189 USPQ 257 (1976); and Anderson’s-Black Rock, Inc. v. Pavement Salvage Co., 396 U.S. 57, 163 USPQ 673 (1969). As stated by the Supreme Court in KSR, “While the sequence of these questions might be reordered in any particular case, the [Graham] factors continue to define the inquiry that controls.”KSR, 550 U.S. at 407, 82 USPQ2d at 1391.

Office Personnel As Factfinders

Office personnel fulfill the critical role of factfinder when resolving the Graham inquiries. It must be remembered that while the ultimate determination of obviousness is a legal conclusion, the underlying Graham inquiries are factual. When making an obviousness rejection, Office personnel must therefore ensure that the written record includes findings of fact concerning the state of the art and the teachings of the references applied. In certain circumstances, it may also be important to include explicit findings as to how a person of ordinary skill would have understood prior art teachings, or what a person of ordinary skill would have known or could have done. Factual findings made by Office personnel are the necessary underpinnings to establish obviousness.

Once the findings of fact are articulated, Office personnel must provide an explanation to support an obviousness rejection under 35 U.S.C. 103. 35 U.S.C. 132 requires that the applicant be notified of the reasons for the rejection of the claim so that he or she can decide how best to proceed. Clearly setting forth findings of fact and the rationale(s) to support a rejection in an Office action leads to the prompt resolution of issues pertinent to patentability.

In short, the focus when making a determination of obviousness should be on what a person of ordinary skill in the pertinent art would have known at the time of the invention, and on what such a person would have reasonably expected to have been able to do in view of that knowledge. This is so regardless of whether the source of that knowledge and ability was documentary prior art, general knowledge in the art, or common sense. What follows is a discussion of the Graham factual inquiries.

A. Determining the Scope and Content of the Prior Art

In determining the scope and content of the prior art, Office personnel must first obtain a thorough understanding of the invention disclosed and claimed in the application under examination by reading the specification, including the claims, to understand what the applicant has invented. See MPEP § 904. The scope of the claimed invention must be clearly determined by giving the claims the “broadest reasonable interpretation consistent with the specification.” See Phillips v. AWH Corp., 415 F.3d 1303, 1316, 75 USPQ2d 1321, 1329 (Fed. Cir. 2005) and MPEP § 2111. Once the scope of the claimed invention is determined, Office personnel must then determine what to search for and where to search.

1. What To Search For:

The search should cover the claimed subject matter and should also cover the disclosed features which might reasonably be expected to be claimed. See MPEP § 904.02. Although a rejection need not be based on a teaching or suggestion to combine, a preferred search will be directed to finding references that provide such a teaching or suggestion if they exist.

2. Where To Search:

Office personnel should continue to follow the general search guidelines set forth in MPEP § 904 to § 904.03 regarding search of the prior art. Office personnel are reminded that, for purposes of 35 U.S.C. 103, prior art can be either in the field of applicant’s endeavor or be reasonably pertinent to the particular problem with which the applicant was concerned. See MPEP § 2141.01(a) for a discussion of analogous art. Furthermore, prior art that is in a field of endeavor other than that of the applicant (as noted by the Court in KSR, “[w]hen a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one,” 550 U.S. at 417, 82 USPQ2d at 1396 (emphasis added)), or solves a problem which is different from that which the applicant was trying to solve, may also be considered for the purposes of 35 U.S.C. 103. (The Court in KSR stated that “[t]he first error…in this case was…holding that courts and patent examiners should look only to the problem the patentee was trying to solve. The Court of Appeals failed to recognize that the problem motivating the patentee may be only one of many addressed by the patent’s subject matter…The second error [was]…that a person of ordinary skill attempting to solve a problem will be led only to those elements of prior art designed to solve the same problem.” 550 U.S. at 420, 82 USPQ2d at 1397. Federal Circuit case law prior to the Supreme Court’s decision in KSR is generally in accord with these statements by the KSR Court. See e.g., In re Dillon, 919 F.2d 688, 693, 16 USPQ2d 1897, 1902 (Fed. Cir. 1990) (en banc) ( "[I]t is not necessary in order to establish a prima facie case of obviousness that both a structural similarity between a claimed and prior art compound (or a key component of a composition) be shown and that there be a suggestion in or expectation from the prior art that the claimed compound or composition will have the same or a similar utility as one newly discovered by applicant " ) (emphasis added); In re Lintner, 458 F.2d 1013, 1018, 173 USPQ 560, 562 (CCPA 1972) (“The fact that [applicant] uses sugar for a different purpose does not alter the conclusion that its use in a prior art composition would be prima facie obvious from the purpose disclosed in the references.”).

For a discussion of what constitutes prior art, see MPEP § 901 to § 901.06(d) and § 21.1 to § 21.9. See MPEP § 2141.01(a) for a discussion of analogous art.

B. Ascertaining the Differences Between the Claimed Invention and the Prior Art

Ascertaining the differences between the claimed invention and the prior art requires interpreting the claim language, see MPEP § 2111, and considering both the invention and the prior art as a whole. See MPEP § 2141.02.

C. Resolving the Level of Ordinary Skill in the Art

Any obviousness rejection should include, either explicitly or implicitly in view of the prior art applied, an indication of the level of ordinary skill. A finding as to the level of ordinary skill may be used as a partial basis for a resolution of the issue of obviousness.

The person of ordinary skill in the art is a hypothetical person who is presumed to have known the relevant art at the time of the invention. Factors that may be considered in determining the level of ordinary skill in the art may 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 re GPAC, 57 F.3d 1573, 1579, 35 USPQ2d 1116, 1121 (Fed. Cir. 1995). "In a given case, every factor may not be present, and one or more factors may predominate.” Id. See also Custom Accessories, Inc. v. Jeffrey-Allan Indust., Inc., 807 F.2d 955, 962, 1 USPQ2d 1196, 1201 (Fed. Cir. 1986); Environmental Designs, Ltd. V. Union Oil Co., 713 F.2d 693, 696, 218 USPQ 865, 868 (Fed. Cir. 1983).

“A person of ordinary skill in the art is also a person of ordinary creativity, not an automaton.”KSR, 550 U.S. at 421, 82 USPQ2d at 1397. “[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle.”Id. at 420, 82 USPQ2d at 1397. Office personnel may also take into account “the inferences and creative steps that a person of ordinary skill in the art would employ.”Id. at 418, 82 USPQ2d at 1396.

In addition to the factors above, Office personnel may rely on their own technical expertise to describe the knowledge and skills of a person of ordinary skill in the art. The Federal Circuit has stated that examiners and administrative patent judges on the Board are “persons of scientific competence in the fields in which they work” and that their findings are “informed by their scientific knowledge, as to the meaning of prior art references to persons of ordinary skill in the art.” In re Berg, 320 F.3d 1310, 1315, 65 USPQ2d 2003, 2007 (Fed. Cir. 2003). In addition, examiners “are assumed to have some expertise in interpreting the references and to be familiar from their work with the level of skill in the art.” PowerOasis, Inc. v. T-Mobile USA, Inc., 522 F.3d 1299, 86 USPQ2d 1385 (Fed. Cir. 2008) (quoting Am. Hoist & Derrick Co. v. Sowa & Sons, 725 F.2d 1350, 1360, 220 USPQ 763, 770 (Fed. Cir. 1984). See MPEP § 2141 for a discussion of the level of ordinary skill.

III. RATIONALES TO SUPPORT REJECTIONS UNDER 35 U.S.C. 103

Once the Graham factual inquiries are resolved, Office personnel must determine whether the claimed invention would have been obvious to one of ordinary skill in the art.

The obviousness analysis cannot be confined by... overemphasis on the importance of published articles and the explicit content of issued patents.. .. . In many fields it may be that there is little discussion of obvious techniques or combinations, and it often may be the case that market demand, rather than scientific literature, will drive design trends.KSR, 550 U.S. at 419, 82 USPQ2d at 1396.

Prior art is not limited just to the references being applied, but includes the understanding of one of ordinary skill in the art. The prior art reference (or references when combined) need not teach or suggest all the claim limitations, however, Office personnel must explain why the difference(s) between the prior art and the claimed invention would have been obvious to one of ordinary skill in the art. The “mere existence of differences between the prior art and an invention does not establish the invention’s nonobviousness.” Dann v. Johnston, 425 U.S. 219, 230, 189 USPQ 257, 261 (1976). The gap between the prior art and the claimed invention may not be “so great as to render the [claim] nonobvious to one reasonably skilled in the art.” Id. In determining obviousness, neither the particular motivation to make the claimed invention nor the problem the inventor is solving controls. The proper analysis is whether the claimed invention would have been obvious to one of ordinary skill in the art after consideration of all the facts. See 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a). Factors other than the disclosures of the cited prior art may provide a basis for concluding that it would have been obvious to one of ordinary skill in the art to bridge the gap. The rationales discussed below outline reasoning that may be applied to find obviousness in such cases.

If the search of the prior art and the resolution of the Graham factual inquiries reveal that an obviousness rejection may be made using the familiar teaching-suggestion-motivation (TSM) rationale, then such a rejection should be made. Although the Supreme Court in KSR cautioned against an overly rigid application of TSM, it also recognized that TSM was one of a number of valid rationales that could be used to determine obviousness. (According to the Supreme Court, establishment of the TSM approach to the question of obviousness “captured a helpful insight.” 550 U.S. at 418, 82 USPQ2d at 1396 (citing In re Bergel, 292 F.2d 955, 956-57, 130 USPQ 206, 207-208 (1961)). Furthermore, the Court explained that “[t]here is no necessary inconsistency between the idea underlying the TSM test and the Graham analysis.” 550 U.S. at 419, 82 USPQ2d at 1396. The Supreme Court also commented that the Federal Circuit “no doubt has applied the test in accord with these principles [set forth in KSR] in many cases.” Id. Office personnel should also consider whether one or more of the other rationales set forth below support a conclusion of obviousness. The Court in KSR identified a number of rationales to support a conclusion of obviousness which are consistent with the proper “functional approach” to the determination of obviousness as laid down in Graham. KSR, 550 U.S. at 415-21, 82 USPQ2d at 1395-97. Note that the list of rationales provided below is not intended to be an all-inclusive list. Other rationales to support a conclusion of obviousness may be relied upon by Office personnel.

The key to supporting any rejection under 35 U.S.C. 103 is the clear articulation of the reason(s) why the claimed invention would have been obvious. The Supreme Court in KSR noted that the analysis supporting a rejection under 35 U.S.C. 103 should be made explicit. The Court quoting In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006), stated that “‘[R]ejections on obviousness cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.’” KSR, 550 U.S. at 418, 82 USPQ2d at 1396. 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.

See MPEP § 2143 for a discussion of the rationales listed above along with examples illustrating how the cited rationales may be used to support a finding of obviousness. See also MPEP § 2144 - § 2144.09 for additional guidance regarding support for obviousness determinations.

IV. APPLICANT’S REPLY

Once Office personnel have established the Graham factual findings and concluded that the claimed invention would have been obvious, the burden then shifts to the applicant to (A) show that the Office erred in these findings or (B) provide other evidence to show that the claimed subject matter would have been nonobvious. 37 CFR 1.111(b) requires applicant to distinctly and specifically point out the supposed errors in the Office’s action and reply to every ground of objection and rejection in the Office action. The reply must present arguments pointing out the specific distinction believed to render the claims patentable over any applied references.

If an applicant disagrees with any factual findings by the Office, an effective traverse of a rejection based wholly or partially on such findings must include a reasoned statement explaining why the applicant believes the Office has erred substantively as to the factual findings. A mere statement or argument that the Office has not established a prima facie case of obviousness or that the Office’s reliance on common knowledge is unsupported by documentary evidence will not be considered substantively adequate to rebut the rejection or an effective traverse of the rejection under 37 CFR 1.111(b). Office personnel addressing this situation may repeat the rejection made in the prior Office action and make the next Office action final. See MPEP § 706.07(a).

V. CONSIDERATION OF APPLICANT’S REBUTTAL EVIDENCE

Office personnel should consider all rebuttal evidence that is timely presented by the applicants when reevaluating any obviousness determination. Rebuttal evidence may include evidence of “secondary considerations,” such as “commercial success, long felt but unsolved needs, [and] failure of others” (Graham v. John Deere Co., 383 U.S. at 17, 148 USPQ at 467), and may also include evidence of unexpected results. As set forth above, Office personnel must articulate findings of fact that support the rationale relied upon in an obviousness rejection. As a result, applicants are likely to submit evidence to rebut the fact finding made by Office personnel. For example, in the case of a claim to a combination, applicants may submit evidence or argument to demonstrate that:

  • (A) one of ordinary skill in the art could not have combined the claimed elements by known methods (e.g., due to technological difficulties);
  • (B) the elements in combination do not merely perform the function that each element performs separately; or
  • (C) the results of the claimed combination were unexpected.

Once the applicant has presented rebuttal evidence, Office personnel should reconsider any initial obviousness determination in view of the entire record. See, e.g., In re Piasecki, 745 F.2d 1468, 1472, 223 USPQ 785, 788 (Fed. Cir. 1984); In re Eli Lilly & Co., 90 F.2d 943, 945, 14 USPQ2d 1741, 1743 (Fed. Cir. 1990). All the rejections of record and proposed rejections and their bases should be reviewed to confirm their continued viability. The Office action should clearly communicate the Office’s findings and conclusions, articulating how the conclusions are supported by the findings. The procedures set forth in MPEP § 706.07(a) are to be followed in determining whether an action may be made final.

See MPEP § 2145 concerning consideration of applicant’s rebuttal evidence. See also MPEP § 716 to § 716.10 regarding affidavits or declarations filed under 37 CFR 1.132 for purposes of traversing grounds of rejection.