MPEP § 2141 — MPEP § 2141
Current through: 2022-07-01

2141-Examination Guidelines for Determining Obviousness Under 35 U.S.C. 103 
 
 

 
 
 
 
 
 
 
 

 

 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 

 Skip over navigation 
 
 
 
 
 
 
 
 search for patents | search for trademarks 

 
 
 
 
 
 
 
 
 
 
 
 Search 
 
 
 

 
 

 
 
 
 
 
 PATENTS 
 
 Patent Search 

 
 Patent Process 

 
 Patent Classification 

 
 Patent Forms 

 
 Statistics 

 
 Electronic Business Center 

 
 Patent Laws, Regulations, Policies & Procedures 

 
 Resources and Guidance 

 
 Office of Data Management 

 
 Announcements 

 
 Initiatives & Events 

 
 International Protection 

 
 Employee Locator 

 
 Contact Patents 

 

 

 
 TRADEMARKS 
 
 Trademark Search 

 
 Trademarks Process 

 
 News & Notices 

 
 Manuals, Guides, Official Gazette 

 
 Laws & Regulations 

 
 Online Filing 

 
 Contact Trademarks 

 

 

 
 IP LAW & POLICY 
 
 Rulemaking 

 
 IP Policy and Enforcement 

 
 Protecting IP Overseas 

 
 Training and Education 

 
 Training Programs & Conferences 

 
 Office of Governmental Affairs 

 
 Office of Chief Economist 

 
 Boards and Counsel 

 

 

 
 PRODUCTS & SERVICES 
 
 Electronic Data Products 

 
 XML Resources 

 
 XML Resources - Retrospective 

 
 USPTO Contact Center Order Form 

 
 Services 

 
 Locate Libraries 

 
 Training/Events 

 
 Online Services Hub 

 

 

 
 INVENTORS 
 
 Patents for Inventors 

 
 Trademarks for Inventors 

 
 Inventors Assistance 

 
 Education and Information 

 
 Scam Prevention 

 
 Pro Se and Pro Bono 

 
 Current Events 

 
 State Resources 

 
 InventorsEye Newsletter 

 

 

 
 NEWS & NOTICES 
 
 Subscription Center 

 
 Press Releases 

 
 Testimony and Speeches 

 
 Director's Forum 

 
 Systems Status 

 
 Emergency Notices 

 
 USPTO Videos 

 
 Official Gazette 

 
 Federal Register Notices 

 
 Event Calendar 

 

 

 
 FAQs 
 
 Patents FAQs 

 
 Trademarks FAQs 

 
 Assignments 

 
 Security 

 
 Musicians and Artists 

 
 Browser Plugins 

 
 Other Web Resources 

 

 

 
 ABOUT US 
 
 USPTO Leadership 

 
 USPTO Organization 

 
 USPTO Offices 

 
 Careers 

 
 Budget, Performance, and Planning 

 
 Statistics 

 
 Vendor Information 

 
 Public Advisory Committees 

 
 National Medal of Technology and Innovation 

 
 IP in Motion 

 
 Contact Us 

 

 

 
 
 

 

 
 

 
 
 
 
 Home Page 

 
 Patents 

 
 Patent Laws, Regulations, Policies & Procedures 

 
 Manual of Patent Examining Procedure 

 Chapter 2100 

 Section 2141 
 

 
 
 
 
 
 2141 Examination Guidelines for Determining Obviousness Under 35 U.S.C.
 103 [R-01.2024]
 

 [Editor Note: This MPEP section is applicable regardless of whether an application
 is examined under the AIA or under pre-AIA law. For applications subject to the first
 inventor to file (FITF) provisions of the AIA, the relevant time is "before the
 effective filing date of the claimed invention". For applications subject to
 pre-AIA 35 U.S.C.
 102 , the relevant time is "at the time of the invention". See
 MPEP §
 2150 et seq. Many of the court decisions discussed in this
 section involved applications or patents subject to pre-AIA 35 U.S.C. 102 . These court
 decisions may be applicable to applications and patents subject to AIA 35 U.S.C.
 102 but the relevant time is before the effective filing date of
 the claimed invention and not at the time of the invention.] 

 
 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. 
 

 
 *****

 
 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 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). 
 

 In another case, the Federal Circuit also stated
 that:
 

 
 “… we conclude that while ‘common sense’ can be
 invoked, even potentially to supply a limitation missing from the prior art, it must
 still be supported by evidence and a reasoned explanation....[T]his is particularly
 true where the missing limitation goes to the heart of an invention.”
 

 
 Arendi v. Apple, 832 F.3d 1355, 1363,
 119 USPQ2d 1822, 1827 (Fed. Cir. 2016).
 

 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 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.) . See also Novartis Pharms. Corp. v.
 West-Ward Pharms. Int'l Ltd., 923 F.3d 1051, 1059, 2019 USPQ2d 171676
 (Fed. Cir. 2019); Apple Inc. v. Samsung Elecs. Co., 839 F.3d 1034,
 1047-48, 120 USPQ2d 1400, 1410 (Fed. Cir. 2016); and Aventis Pharma S.A. v.
 Hospira, Inc., 675 F.3d 1324, 1332, 102 USPQ2d 1445, 1449 (Fed. Cir.
 2012).
 

 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, § 103 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 INQUIRIES OF GRAHAM v. JOHN DEERE CO. An invention that would have been obvious to a person of ordinary
 skill at the relevant time 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; 

 (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
 determined 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, these factual inquiries, as well as secondary considerations when
 present, must be analyzed. 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
 the applicant 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 relevant time, 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 has been 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 the
 inventor’s endeavor or be reasonably pertinent to the particular problem
 with which the inventor was concerned. See MPEP §
 2141.01(a) for a discussion of analogous art and
 MPEP §
 1504.03 for a discussion of analogous art for
 design applications. Furthermore, prior art that is in a field of endeavor
 other than that of the inventor (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 inventor 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, 1016, 173 USPQ 560, 562 (CCPA 1972)
 (“The fact that appellant 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
 §
 2121 to § 2129 . See
 MPEP §
 2141.01(a) for a discussion of analogous art and
 MPEP §
 1504.03 for a discussion of analogous art for
 design applications.
 

 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. See MPEP § 2141.03 , subsection II,
 regarding implicit 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 relevant time.
 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 § 2141.03 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 as
 of the relevant time 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
 as of the relevant time 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 is appropriate. 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 supports 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. Consistent with KSR, the Federal Circuit stated that the
 obviousness analysis is not “confined by a formalistic conception of the words teaching,
 suggestion, and motivation.” Intel Corp. v. Qualcomm Inc., 21 F.4th
 784, 795, 2021 USPQ2d 1259 (Fed. Cir. 2021) (quoting KSR, 550 U.S. at
 419, 82 USPQ2d at 1396). See also In re Ethicon, Inc., 844 F.3d 1344,
 1350, 121 USPQ2d 1139, 1143 (Fed. Cir. 2017) (recalling that the Supreme Court has
 instructed decisionmakers to “apply ‘an expansive and flexible approach’ to
 obviousness”) (quoting KSR, 550 U.S. at 415, 82 USPQ2d at 1395). 
 

 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. See also Adapt Pharma Operations Ltd. v. Teva Pharms. USA,
 Inc., 25 F.4th 1354, 1365, 2022 USPQ2d 144 (Fed. Cir. 2022) (stating that a
 determination of obviousness “requires ‘identify[ing] a reason that would have prompted
 a person of ordinary skill in the relevant field to combine the elements in the way the
 claimed new invention does’” (quoting KSR, 550 U.S. at 418, 82 USPQ2d
 at 1395). Examples of 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 issued a rejection that establishes the
 Graham factual findings and concludes, in view of the relevant
 evidence of record at that time, that the claimed invention would have been obvious as
 of the relevant time, 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) .
 

 An applicant’s reply could also establish that a
 disclosure relied on in an obviousness rejection is not in fact prior art in view of a
 35 U.S.C.
 102(b) exception, or that subject matter, although prior art, is
 disqualified for use in an obviousness rejection in view of pre-AIA 35 U.S.C.
 103(c) . See MPEP §§ 2146 , 2153.01 
 and 2154.02 . See also MPEP §
 2155 regarding affidavits or declarations under
 37 CFR
 1.130 to overcome prior art rejections.
 

 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., 902 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. 
 

 
 2141.01 Scope and Content of the Prior Art [R-01.2024]

 [Editor Note: This MPEP section is applicable regardless of whether an
 application is examined under the AIA or under pre-AIA law. For applications subject
 to the first inventor to file (FITF) provisions of the AIA, the relevant time is
 "before the effective filing date of the claimed invention". For applications subject
 to pre-AIA 35
 U.S.C. 102 , the relevant time is "at the time of the
 invention". See MPEP § 2150 et seq. Many of the
 court decisions discussed in this section involved applications or patents subject to
 pre-AIA 35
 U.S.C. 102 . These court decisions may be applicable to
 applications and patents subject to AIA 35 U.S.C. 102 but the
 relevant time is before the effective filing date of the claimed invention and not at
 the time of the invention.] 

 I. PRIOR ART AVAILABLE UNDER 35 U.S.C. 102 IS AVAILABLE UNDER 35 U.S.C.
 103 “Before answering Graham’s ‘content’ inquiry, it
 must be known whether a patent or publication is in the prior art under
 35 U.S.C. §
 102 .” Panduit Corp. v. Dennison Mfg. Co., 
 810 F.2d 1561, 1568, 1 USPQ2d 1593, 1597 (Fed. Cir.), cert.
 denied, 481 U.S. 1052 (1987). Subject matter that is prior art under
 35 U.S.C.
 102 can be used to support a rejection under section
 103 . Ex parte Andresen, 212 USPQ 100, 102
 (Bd. Pat. App. & Inter. 1981) (“it appears to us that the commentator [of 35
 U.S.C.A.] and the [congressional] committee viewed section 103 as
 including all of the various bars to a patent as set forth in section 102 .”).
 See also In re Wertheim, 646 F.2d 527, 532, 209 USPQ 554, 560
 (CCPA 1981) (“Commensurate with the Senate Report and Mr. Federico's commentary, we
 have held that the term ‘prior art’ refers ‘to at least the statutory prior art
 material named in §
 102 .’”); and In re Hoeksema, 399 F.2d 269,
 273, 158 USPQ 596, 600 (CCPA 1968) (“[w]hile 35 U.S.C. 102 is not directly
 involved in the issue on review, the conditions for patentability, novelty and loss
 of right to patent, there stated, may have relevance as to the disclosure which must
 be found in the prior art to find obviousness of an invention under section
 103 .”). 
 

 Furthermore, admitted prior art can be relied upon for both
 anticipation and obviousness determinations, regardless of whether the admitted prior
 art would otherwise qualify as prior art under the statutory categories of
 35 U.S.C.
 102 . Riverwood Int’l Corp. v. R.A. Jones &
 Co., 324 F.3d 1346, 1354, 66 USPQ2d 1331, 1337 (Fed. Cir. 2003);
 Constant v. Advanced Micro-Devices Inc., 848 F.2d 1560, 1570, 7
 USPQ2d 1057, 1063 (Fed. Cir. 1988). See MPEP § 2129 for discussion of
 admissions as prior art.
 

 An obviousness rejection is ordinarily based on a disclosure that
 qualifies as prior art under 35 U.S.C. 102 or
 pre-AIA 35
 U.S.C. 102 . If it is established that a disclosure does not
 qualify as prior art under an appropriate section of 35 U.S.C.
 102 , then the disclosure is also not prior art that can be used
 in an obviousness rejection. For instance, for a claimed invention subject to
 35
 U.S.C. 102 , a 35 U.S.C. 102(a)(2) reference
 used in an anticipation rejection but overcome by submitting a declaration under
 37 CFR
 1.130(a) cannot be used in an obviousness rejection. Likewise,
 for a claimed invention subject to pre-AIA 35 U.S.C. 102 , a
 pre-AIA 35
 U.S.C. 102(a) reference used in an anticipation rejection but
 overcome by submitting a declaration under 37 CFR 1.131 cannot be used in an
 obviousness rejection.
 

 For an overview of what constitutes prior art under
 35 U.S.C.
 102, see MPEP § 901 - § 901.06(d) ,
 § 2121 - § 2129 and §
 2151 - § 2155 .
 

 II. SUBSTANTIVE CONTENT OF THE PRIOR ART See MPEP § 2121 - § 2129 for case law relating to the
 substantive content of the prior art (e.g., availability of inoperative devices,
 extent to which prior art must be enabling, broad disclosure rather than preferred
 embodiments, admissions, etc.).
 

 III. CONTENT OF THE PRIOR ART IS DETERMINED AT THE RELEVANT TIME TO AVOID
 HINDSIGHT The purpose of the pre-AIA 35 U.S.C. 103(a) 
 requirement “at the time the invention was made” is to avoid impermissible hindsight.
 Likewise, the AIA 35 U.S.C. 103 requirement
 “before the effective filing date of the claimed invention” serves the same purpose.
 See MPEP §
 2145 , subsection X.A. for a discussion of rebutting
 applicants’ arguments that a rejection is based on hindsight.
 

 In the pre-AIA context, the Federal Circuit stated, “[i]t is
 difficult but necessary that the decisionmaker forget what he or she has been taught
 . . . about the claimed invention and cast the mind back to the time the invention
 was made (often as here many years), to occupy the mind of one skilled in the art.
 ...” W.L. Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d
 1540, 1553, 220 USPQ 303, 313 (Fed. Cir. 1983), cert. denied, 469
 U.S. 851 (1984). Although the AIA has changed the relevant time focus to “before the
 effective filing date of the claimed invention,” the observation expressed by the
 Federal Circuit otherwise continues to apply. 
 

 IV. PRE-AIA 35 U.S.C. 103(c) COMMON OWNERSHIP— REQUIRED FOR THE CONDITIONS OF
 PRE-AIA 35 U.S.C. 103(c) An applicant subject to pre-AIA 35 U.S.C. 102 who wants
 to rely on pre-AIA
 35 U.S.C. 103(c) to overcome an obviousness rejection has the
 burden of establishing that subject matter which only qualifies as prior art under
 subsection (e) , (f) or (g) of
 pre-AIA 35
 U.S.C. 102 used in a rejection under pre-AIA 35 U.S.C.
 103(a) and the claimed invention were, at the time the
 invention was made, owned by the same person or subject to an obligation of
 assignment to the same person. Likewise, an applicant who wants to rely on the joint
 research provisions of pre-AIA 35 U.S.C. 103(c) (for
 applications pending on or after December 10, 2004) has the burden of establishing
 that:
 

 
 (A) the claimed invention was made by or on behalf of parties to a
 joint research agreement that was in effect on or before the date the claimed
 invention was made;
 

 (B) the claimed invention was made as a result of activities
 undertaken within the scope of the joint research agreement; and
 

 (C) the application for patent for the claimed invention discloses
 or is amended to disclose the names of the parties to the joint research
 agreement. 
 

 
 These prior art disqualifications under pre-AIA 35 U.S.C
 103(c) are only applicable for subject matter which only
 qualifies as prior art under subsection (e) , (f) or
 (g) of pre-AIA 35 U.S.C. 102 and is used
 in a rejection under pre-AIA 35 U.S.C. 103(a) .
 

 Note that for applications filed prior to November 29, 1999, and
 granted as patents prior to December 10, 2004 ,
 pre-AIA 35
 U.S.C. 103(c) is limited on its face to subject matter
 developed by another person which qualifies as prior art only under subsection
 (f) or (g) of pre-AIA 35 U.S.C.
 102 . See MPEP § 2146.01 . See also In
 re Bartfeld, 925 F.2d 1450, 1453-54, 17 USPQ2d 1885, 1888 (Fed. Cir.
 1991) (Applicant attempted to overcome a pre-AIA 35 U.S.C.
 102(e) / 103 rejection with a terminal
 disclaimer by alleging that the public policy intent of pre-AIA 35 U.S.C
 103(c) was to prohibit the use of “secret” prior art in
 obviousness determinations. The court rejected this argument, holding “We may not
 disregard the unambiguous exclusion of § 102(e) from the statute’s
 purview.”).
 

 See MPEP § 2146.02 for the requirements
 which must be met to establish common ownership or a joint research agreement.
 

 
 2141.01(a) Analogous and Nonanalogous Art [R-01.2024]

 [Editor Note: This MPEP section is applicable regardless of whether an
 application is examined under the AIA or under pre-AIA law. For applications
 subject to the first inventor to file (FITF) provisions of the AIA, the relevant
 time is "before the effective filing date of the claimed invention". For
 applications subject to pre-AIA 35 U.S.C. 102 , the
 relevant time is "at the time of the invention". See MPEP §
 2150 et seq. Many of the court decisions discussed in
 this section involved applications or patents subject to pre-AIA 35 U.S.C.
 102 . These court decisions may be applicable to applications
 and patents subject to AIA 35 U.S.C. 102 but the
 relevant time is before the effective filing date of the claimed invention and not
 at the time of the invention.] 

 I. TO RELY ON A REFERENCE UNDER 35 U.S.C. 103, IT MUST BE ANALOGOUS ART TO THE
 CLAIMED INVENTION In order for a reference to be proper for use in an obviousness
 rejection under 35 U.S.C. 103 , the reference must be analogous art to the
 claimed invention. In re Bigio, 381 F.3d 1320, 1325, 72 USPQ2d
 1209, 1212 (Fed. Cir. 2004). A reference is analogous art to the claimed invention
 if: (1) the reference is from the same field of endeavor as the claimed invention
 (even if it addresses a different problem); or (2) the reference is reasonably
 pertinent to the problem faced by the inventor (even if it is not in the same
 field of endeavor as the claimed invention). Note that “same field of endeavor”
 and “reasonably pertinent” are two separate tests for establishing analogous art;
 it is not necessary for a reference to fulfill both tests in order to qualify as
 analogous art. See Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
 The examiner must determine whether a reference is analogous art to the claimed
 invention when analyzing the obviousness of the subject matter under examination.
 When more than one prior art reference is used as the basis of an obviousness
 rejection, it is not required that the references be analogous art to each other.
 See Sanofi-Aventis Deutschland GMbH v. Mylan Pharms. Inc., 66
 F.4th 1373, 1380, 2023 USPQ2d 552 (Fed. Cir. 2023) and Corephotonics,
 Ltd. v. Apple Inc., 84 F.4th 990, 1007, 2023 USPQ2d 1202 (Fed. Cir.
 2023). If a reference is not analogous art to the claimed invention, it may not be
 used in an obviousness rejection under 35 U.S.C. 103 . However, there
 is no analogous art requirement for a reference being applied in an anticipation
 rejection under 35 U.S.C. 102 . In re
 Schreiber, 128 F.3d 1473, 1478, 44 USPQ2d 1429, 1432 (Fed. Cir.
 1997).
 

 When determining whether the “relevant field of
 endeavor” test is met, the examiner should consider “explanations of the
 invention’s subject matter in the patent application, including the embodiments,
 function, and structure of the claimed invention.” Airbus S.A.S. v.
 Firepass Corp., 941 F.3d 1374, 1380, 2019 USPQ2d 430083 (Fed. Cir.
 2019) (quoting Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212).
 When determining whether a prior art reference meets the “same field of endeavor”
 test for the analogous art, the primary focus is on what the reference discloses.
 Airbus, 41 F.3d at 1380. The examiner must consider the
 disclosure of each reference “in view of the ‘the reality of the circumstances.’”
 Airbus, 41 F.3d at 1380 (quoting Bigio, 
 381 F.3d at 1326, 72 USPQ2d at 1212). These circumstances are to be weighed “from
 the vantage point of the common sense likely to be exerted by one of ordinary
 skill in the art in assessing the scope of the endeavor.”
 Airbus, 41 F.3d at 1380. See also Donner
 Technology, LLC v. Pro Stage Gear, LLC, 979 F.3d 1353, 2020 USPQ2d
 11335 (Fed. Cir. 2020); Sanofi-Aventis, 66 F.4th at 1378; and
 Netflix, Inc. v. DivX, LLC, 80 F.4th 1352, 1358-59, 2023
 USPQ2d 1057 (Fed. Cir. 2023) (“The field of endeavor is ‘not limited to the
 specific point of novelty, the narrowest possible conception of the field, or the
 particular focus within a given field.’”) (quoting Unwired Planet, LLC v.
 Google Inc., 841 F.3d 995, 1001, 120 USPQ2d 1593, 1597 (Fed. Cir.
 2016)).
 

 As for the “reasonably pertinent” test, the examiner
 should consider the problem faced by the inventor, as reflected - either
 explicitly or implicitly - in the specification. In order for a reference to be
 "reasonably pertinent" to the problem, it must "logically [] have commended itself
 to an inventor's attention in considering his problem." In re ICON Health
 and Fitness, Inc., 496 F.3d 1374, 1379-80 (Fed. Cir. 2007) (quoting
 In re Clay, 966 F.2d 656,658, 23 USPQ2d 1058, 1061 (Fed.
 Cir. 1992)). See also In re Klein, 647 F.3d 1343, 1348, 98
 USPQ2d 1991, 1993 (Fed. Cir. 2011) An inventor is not expected to have been aware
 of all prior art outside of the field of endeavor. Airbus, 41
 F.3d at 1380-82. A reference outside of the field of endeavor is reasonably
 pertinent if a person of ordinary skill would have consulted it and applied its
 teachings when faced with the problem that the inventor was trying to solve.
 Airbus, 41 F.3d at 1380-82. In order to support a
 determination that a reference is reasonably pertinent, it may be appropriate to
 include a statement of the examiner's understanding of the problem. The question
 of whether a reference is reasonably pertinent often turns on how the problem to
 be solved is perceived. If the problem to be solved is viewed in a narrow or
 constrained way, and such a view is not consistent with the specification, the
 scope of available prior art may be inappropriately limited. It may be necessary
 for the examiner to explain why an inventor seeking to solve the identified
 problem would have looked to the reference in an attempt to find a solution to the
 problem, i.e., factual reasons why the prior art is pertinent to the identified
 problem. See Donner Tech., LLC v. Pro Stage Gear, LLC, 979 F.3d
 1353, 1359, 2020 USPQ2d 11335 (Fed. Cir. 2020) (“Thus, when addressing whether a
 reference is analogous art with respect to the claimed invention under a
 reasonable-pertinence theory, the problems to which both relate must be identified
 and compared.”). 
 

 The Supreme Court’s decision in KSR Int'l
 Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007), did not
 change the test for analogous art as stated in Bigio. Under
 Bigio, a reference need not be from the same field of
 endeavor as the claimed invention in order to be analogous art.
 Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212. This is
 consistent with the Supreme Court's instruction in KSR that
 "[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." KSR, 550 U.S. at 417, 82 USPQ2d at 1396. The Federal
 Circuit reads KSR as “direct[ing] us to construe the scope of
 analogous art broadly” because “ familiar items may have obvious uses
 beyond their primary purposes, and a person of ordinary skill often
 will be able to fit the teachings of multiple patents together like pieces of a
 puzzle.” Wyers v. Master Lock Co., 616 F.3d 1231, 1238, 95
 USPQ2d 1525, 1530 (Fed. Cir. 2010) (quoting KSR, 550 U.S. at
 402, 127 S. Ct. at 1727).
 

 Any argument by the applicant that the examiner has
 misconstrued the problem to be solved, and as a result has improperly relied on
 nonanalogous art, should be fully considered in light of the specification. In
 evaluating the applicant's argument, the examiner should look to the teachings of
 the specification and the inferences that would reasonably have been drawn from
 the specification by a person of ordinary skill in the art as a guide to
 understanding the problem to be solved. A prior art reference not in the same
 field of endeavor as the claimed invention must be reasonably pertinent to the
 problem to be solved in order to qualify as analogous art and be applied in an
 obviousness rejection.
 

 II. CONSIDER SIMILARITIES AND DIFFERENCES IN STRUCTURE AND FUNCTION While Patent Office classification of references and the
 cross-references in the official search notes of the class definitions are some
 evidence of “nonanalogy” or “analogy” respectively, the court has found “the
 similarities and differences in structure and function of the inventions disclosed
 in the references to carry far greater weight.” In re Ellis, 
 476 F.2d 1370, 1372, 177 USPQ 526, 527 (CCPA 1973) (The structural similarities
 and functional overlap between the structural gratings shown by one reference and
 the shoe scrapers of the type shown by another reference were readily apparent,
 and therefore the arts to which the reference patents belonged were reasonably
 pertinent to the art with which appellant’s invention dealt (pedestrian floor
 gratings).).
 

 III. ANALOGY IN THE CHEMICAL ARTS Examples of analogous art in the chemical arts include:
 Ex parte Bland, 3 USPQ2d 1103 (Bd. Pat App. & Inter.
 1986) (Claims were drawn to a particulate composition useful as a preservative for
 an animal foodstuff (or a method of inhibiting fungus growth in an animal
 foodstuff therewith) comprising verxite having absorbed thereon propionic acid.
 All references were concerned with absorbing biologically active materials on
 carriers, and therefore the teachings in each of the various references would have
 been pertinent to the problems in the other references and the invention at
 hand.); Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 218
 USPQ 871 (Fed. Cir. 1983) (Problem confronting inventor was preventing
 electrostatic buildup in PTFE tubing caused by hydrocarbon fuel flow while
 precluding leakage of fuel. Two prior art references relied upon were in the
 rubber hose art, both referencing the problem of electrostatic buildup caused by
 fuel flow. The court found that because PTFE and rubber are used by the same hose
 manufacturers and experience the same and similar problems, a solution found for a
 problem experienced with either PTFE or rubber hosing would be looked to when
 facing a problem with the other.); In re Mlot-Fijalkowski, 676
 F.2d 666, 213 USPQ 713 (CCPA 1982) (Problem faced by inventor was enhancement and
 immobilization of dye penetrant indications. References which taught the use of
 dyes and finely divided developer materials to produce colored images preferably
 in, but not limited to, the duplicating paper art were properly relied upon
 because the court found that inventor's problem was one of dye chemistry, and a
 search for its solution would include the dye arts in general.).
 

 IV. ANALOGY IN THE MECHANICAL ARTS Examples of analogous art in the mechanical arts include:
 Stevenson v. Int'l Trade Comm., 612 F.2d 546, 550, 204 USPQ
 276, 280 (CCPA 1979) (“In a simple mechanical invention a broad spectrum of prior
 art must be explored and it is reasonable to permit inquiry into other areas where
 one of ordinary skill in the art would be aware that similar problems exist.”).
 See also In re Bigio, 381 F.3d 1320, 1325-26, 72 USPQ2d 1209,
 1211-12 (Fed. Cir. 2004). The patent application claimed a "hair brush" having a
 specific bristle configuration. The Board affirmed the examiner’s rejection of the
 claims as being obvious in view of prior art patents disclosing toothbrushes.
 Id. at 1323, 72 USPQ2d at 1210. The appellant disputed that
 the patent references constituted analogous art. On appeal, the court upheld the
 Board’s interpretation of the claim term “hair brush” to encompass any brush that
 may be used for any bodily hair, including facial hair. Id. at
 1323-24, 72 USPQ2d at 1211. With this claim interpretation, the court applied the
 “field of endeavor test” for analogous art and determined that the references were
 within the field of the inventor’s endeavor and hence were analogous art because
 toothbrushes are structurally similar to small brushes for hair, and a toothbrush
 could be used to brush facial hair. Id. at 1326, 72 USPQ2d at
 1212.
 

 Also see In re Deminski, 796 F.2d 436, 230
 USPQ 313 (Fed. Cir. 1986) (Appellent's claims related to double-acting high
 pressure gas transmission line compressors in which the valves could be removed
 easily for replacement. The Board relied upon references which taught either a
 double-acting piston pump or a double-acting piston compressor. The court agreed
 that since the cited pumps and compressors have essentially the same function and
 structure, the field of endeavor includes both types of double-action piston
 devices for moving fluids.); Pentec, Inc. v. Graphic Controls
 Corp., 776 F.2d 309, 227 USPQ 766 (Fed. Cir. 1985) (Claims at issue
 were directed to an instrument marker pen body, the improvement comprising a pen
 arm holding means having an integrally molded hinged member for folding over
 against the pen body. Although the patent owners argued the hinge and fastener art
 was nonanalogous, the court held that the problem confronting the inventor was the
 need for a simple holding means to enable frequent, secure attachment and easy
 removal of a marker pen to and from a pen arm, and one skilled in the pen art
 trying to solve that problem would have looked to the fastener and hinge art.);
 and Ex parte Goodyear Tire & Rubber Co., 230 USPQ 357 (Bd.
 Pat. App. & Inter. 1985) (A reference in the clutch art was held reasonably
 pertinent to the friction problem faced by the inventor, whose claims were
 directed to a braking material, because brakes and clutches utilize interfacing
 materials to accomplish their respective purposes.).
 

 V. ANALOGY IN THE ELECTRICAL ARTS See, for example, Medtronic, Inc. v. Cardiac
 Pacemakers, 721 F.2d 1563, 220 USPQ 97 (Fed. Cir. 1983) (Patent
 claims were drawn to a cardiac pacemaker which comprised, among other components,
 a runaway inhibitor means for preventing a pacemaker malfunction from causing
 pulses to be applied at too high a frequency. Two references disclosed circuits
 used in high power, high frequency devices which inhibited the runaway of pulses
 from a pulse source. The court held that one of ordinary skill in the pacemaker
 designer art faced with a rate-limiting problem would look to the solutions of
 others faced with rate limiting problems, and therefore the references were in an
 analogous art.).
 

 VI. EXAMPLES OF ANALOGY IN THE DESIGN ARTS See MPEP § 1504.03 for a discussion
 of the relevant case law setting forth the general requirements for analogous art
 in design applications.
 

 

 

 
 2141.02 Differences Between Prior Art and Claimed Invention [R-01.2024]

 [Editor Note: This MPEP section is applicable regardless of whether an
 application is examined under the AIA or under pre-AIA law. For applications subject
 to the first inventor to file (FITF) provisions of the AIA, the relevant time is
 "before the effective filing date of the claimed invention". For applications subject
 to pre-AIA 35
 U.S.C. 102 , the relevant time is "at the time of the
 invention". See MPEP § 2150 et seq. Many of the
 court decisions discussed in this section involved applications or patents subject to
 pre-AIA 35
 U.S.C. 102 . These court decisions may be applicable to
 applications and patents subject to AIA 35 U.S.C. 102 but the
 relevant time is before the effective filing date of the claimed invention and not at
 the time of the invention.] 

 Ascertaining the differences between the prior art and the claims at
 issue requires interpreting the claim language, and considering both the invention and
 the prior art references as a whole. See MPEP § 2111 - § 2116.01 for case
 law pertaining to claim interpretation. See also MPEP § 2143.03 for examples of types of
 claim language that may raise a question as to its limiting effect.
 

 I. THE CLAIMED INVENTION AS A WHOLE MUST BE CONSIDERED In determining the differences between the prior art and the claims,
 the question under 35 U.S.C. 103 is not whether the differences
 themselves would have been obvious, but whether the claimed
 invention as a whole would have been obvious.
 Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 218 USPQ 871
 (Fed. Cir. 1983); Schenck v. Nortron Corp., 713 F.2d 782, 218 USPQ
 698 (Fed. Cir. 1983) (Claims were directed to a vibratory testing machine (a
 hard-bearing wheel balancer) comprising a holding structure, a base structure, and a
 supporting means which form “a single integral and gaplessly continuous piece.”
 Nortron argued the invention is just making integral what had
 been made in four bolted pieces, improperly limiting the focus to a structural
 difference from the prior art and failing to consider the invention as a whole. The
 prior art perceived a need for mechanisms to dampen resonance, whereas the inventor
 eliminated the need for dampening via the one-piece gapless support structure.
 “Because that insight was contrary to the understandings and expectations of the art,
 the structure effectuating it would not have been obvious to those skilled in the
 art.” 713 F.2d at 785, 218 USPQ at 700 (citations omitted).).
 

 See also In re Hirao, 535 F.2d 67, 190 USPQ 15
 (CCPA 1976) (Claims were directed to a three step process for preparing sweetened
 foods and drinks. The first two steps were directed to a process of producing high
 purity maltose (the sweetener), and the third was directed to adding the maltose to
 foods and drinks. The parties agreed that the first two steps were nonobvious but
 formed a known product and the third step was obvious. The Solicitor argued the
 preamble was directed to a process for preparing foods and drinks sweetened mildly
 and thus the specific method of making the high purity maltose (the first two steps
 in the claimed process) should not be given weight, analogizing with
 product-by-process claims. The court disagreed and held “due to the admitted
 unobviousness of the first two steps of the claimed combination of steps, the subject
 matter as a whole would not have been obvious to one of
 ordinary skill in the art at the time the invention was made.” 535 F.2d at 69, 190
 USPQ at 17 (emphasis in original). The preamble only recited the purpose of the
 process and did not limit the body of the claim. Therefore, the claimed process was a
 three-step process, not the product formed by two steps of the process or the third
 step of using that product.). 
 

 II. DISTILLING THE INVENTION DOWN TO A “GIST” OR “THRUST” OF AN INVENTION
 DISREGARDS “AS A WHOLE” REQUIREMENT Distilling an invention down to the “gist” or “thrust” of an
 invention disregards the requirement of analyzing the subject matter “as a whole.”
 W.L. Gore & Assoc., Inc. v. Garlock, Inc., 721 F.2d 1540,
 220 USPQ 303 (Fed. Cir. 1983), cert. denied, 469 U.S. 851 (1984)
 (restricting consideration of the claims to a 10% per second rate of stretching of
 unsintered PTFE and disregarding other limitations resulted in treating claims as
 though they read differently than allowed); Bausch & Lomb v. Barnes-Hind/Hydrocurve, Inc., 796 F.2d 443, 447-49, 230 USPQ 416,
 419-20 (Fed. Cir. 1986), cert. denied, 484 U.S. 823 (1987)
 (District court focused on the “concept of forming ridgeless depressions having
 smooth rounded edges using a laser beam to vaporize the material,” but “disregarded
 express limitations that the product be an ophthalmic lens formed of a transparent
 cross-linked polymer and that the laser marks be surrounded by a smooth surface of
 unsublimated polymer.”). See also Jones v. Hardy, 727 F.2d 1524,
 1530, 220 USPQ 1021, 1026 (Fed. Cir. 1984) (“treating the advantage as the invention
 disregards the statutory requirement that the invention be viewed ‘as a whole’”);
 Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1 USPQ2d
 1593 (Fed. Cir. 1987), cert. denied, 481 U.S. 1052 (1987)
 (district court improperly distilled claims down to a one word solution to a
 problem).
 

 III. DISCOVERING SOURCE/CAUSE OF A PROBLEM IS PART OF “AS A WHOLE” INQUIRY “[A] patentable invention may lie in the discovery of the source of
 a problem even though the remedy may be obvious once the source of the problem is
 identified. This is part of the ‘subject matter as a whole’
 which should always be considered in determining the obviousness of an invention
 under 35 U.S.C. §
 103 .” In re Sponnoble, 405 F.2d 578, 585,
 160 USPQ 237, 243 (CCPA 1969). However, “discovery of the cause of a problem . . does
 not always result in a patentable invention. . . . [A] different situation exists
 where the solution is obvious from prior art which contains the same
 solution for a similar problem .” In re Wiseman, 596
 F.2d 1019, 1022, 201 USPQ 658, 661 (CCPA 1979) (emphasis in original). 
 

 In In re Sponnoble, the claim was directed to a
 plural compartment mixing vial wherein a center seal plug was placed between two
 compartments for temporarily isolating a liquid-containing compartment from a
 solids-containing compartment. The claim differed from the prior art in the selection
 of butyl rubber with a silicone coating as the plug material instead of natural
 rubber. The prior art recognized that leakage from the liquid to the solids
 compartment was a problem, and considered the problem to be a result of moisture
 passing around the center plug because of microscopic fissures
 inherently present in molded or blown glass. The court found the inventor discovered
 the cause of moisture transmission was through the center
 plug, and there was no teaching in the prior art which would suggest the necessity of
 selecting applicant's plug material which was more impervious to liquids than the
 natural rubber plug of the prior art.
 

 In In re Wiseman, 596 F.2d at 1022, 201 USPQ at
 661, claims directed to grooved carbon disc brakes wherein the grooves were provided
 to vent steam or vapor during a braking action to minimize fading of the brakes were
 rejected as obvious over a reference showing carbon disc brakes without grooves in
 combination with a reference showing grooves in noncarbon disc brakes for the purpose
 of cooling the faces of the braking members and eliminating dust, thereby reducing
 fading of the brakes. The court affirmed the rejection, holding that even if the
 inventor discovered the cause of a problem, the solution would have been obvious from
 the prior art which contained the same solution (inserting grooves in disc brakes)
 for a similar problem.
 

 IV. APPLICANTS ALLEGING DISCOVERY OF A SOURCE OF A PROBLEM MUST PROVIDE
 SUBSTANTIATING EVIDENCE Applicants who allege the inventor discovered the source of a
 problem must provide evidence substantiating the allegation, either by way of
 affidavits or declarations, or by way of a clear and persuasive assertion in the
 specification. In re Wiseman, 596 F.2d 1019, 201 USPQ 658 (CCPA
 1979) (unsubstantiated statement of counsel was insufficient to show appellants
 discovered source of the problem); In re Kaslow, 707 F.2d 1366,
 217 USPQ 1089 (Fed. Cir. 1983) (Claims were directed to a method for redeeming
 merchandising coupons which contain a UPC “5-by-5” bar code wherein, among other
 steps, the memory at each supermarket would identify coupons by manufacturer and
 transmit the data to a central computer to provide an audit, thereby eliminating the
 need for clearinghouses and preventing retailer fraud. In challenging the propriety
 of an obviousness rejection, appellant argued he discovered the source of a problem
 (retailer fraud and manual clearinghouse operations) and its solution. The court
 found appellant’s specification did not support the argument that he discovered the
 source of the problem with respect to retailer fraud, and that the claimed invention
 failed to solve the problem of manual clearinghouse operations.).
 

 V. DISCLOSED INHERENT PROPERTIES ARE PART OF “AS A WHOLE” INQUIRY “In determining whether the invention as a whole would have been
 obvious under 35
 U.S.C. 103 , we must first delineate the invention as a whole.
 In delineating the invention as a whole, we look not only to the subject matter which
 is literally recited in the claim in question... but also to those properties of the
 subject matter which are inherent in the subject matter and are
 disclosed in the specification. . . Just as we look to a chemical and its properties
 when we examine the obviousness of a composition of matter claim, it is this
 invention as a whole, and not some part of it, which must be
 obvious under 35
 U.S.C. 103 .” In re Antonie, 559 F.2d 618,
 620, 195 USPQ 6, 8 (CCPA 1977) (emphasis in original) (citations omitted) (The
 claimed wastewater treatment device had a tank volume to contactor area of 0.12
 gal./sq. ft. The court found the invention as a whole was the ratio of 0.12 and its
 inherent property that the claimed devices maximized treatment capacity regardless of
 other variables in the devices. The prior art did not recognize that treatment
 capacity was a function of the tank volume to contactor ratio, and therefore the
 parameter optimized was not recognized in the art to be a result-effective
 variable.). Note, however, that after KSR, the presence of a known
 result-effective variable would be one, but not necessarily the only, motivation for
 a person of ordinary skill in the art to experiment to reach another workable product
 or process. See MPEP §
 2144.05 , subsection II.B. See also In re
 Papesch, 315 F.2d 381, 391, 137 USPQ 43, 51 (CCPA 1963) (“From the
 standpoint of patent law, a compound and all its properties are inseparable.”).
 

 Obviousness cannot be predicated on what is not known at the
 relevant time, even if the inherency of a certain feature is later established. See
 In re Rijckaert, 9 F.3d 1531, 28 USPQ2d 1955 (Fed. Cir. 1993).
 See MPEP §
 2112 for the requirements of rejections based on
 inherency.
 

 VI. PRIOR ART MUST BE CONSIDERED IN ITS ENTIRETY, INCLUDING DISCLOSURES THAT TEACH
 AWAY FROM THE CLAIMS A prior art reference must be considered in its entirety, i.e., as a
 whole , including portions that would lead away from the
 claimed invention. W.L. Gore & Assoc., Inc. v. Garlock, Inc., 
 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983), cert. denied, 469
 U.S. 851 (1984) (Claims were directed to a process of producing a porous article by
 expanding shaped, unsintered, highly crystalline poly(tetrafluoroethylene) (PTFE) by
 stretching said PTFE at a 10% per second rate to more than five times the original
 length. The prior art teachings with regard to unsintered PTFE indicated the material
 does not respond to conventional plastics processing, and the material should be
 stretched slowly. A reference teaching rapid stretching of conventional plastic
 polypropylene with reduced crystallinity combined with a reference teaching
 stretching unsintered PTFE would not suggest rapid stretching of highly crystalline
 PTFE, in light of the disclosures in the art that teach away from the invention,
 i.e., that the conventional polypropylene should have reduced crystallinity before
 stretching, and that PTFE should be stretched slowly). Allied Erecting v.
 Genesis Attachments, 825 F.3d 1373, 1381, 119 USPQ2d 1132, 1138 (Fed.
 Cir. 2016) (“Although modification of the movable blades may impede the quick change
 functionality disclosed by Caterpillar, ‘[a] given course of action often has
 simultaneous advantages and disadvantages, and this does not necessarily obviate
 motivation to combine.’” (quoting Medichem, S.A. v. Rolabo, S.L., 
 437 F.3d 1157, 1165, 77 USPQ2d 1865, 1870 (Fed Cir. 2006) (citation omitted))).
 

 However, “the prior art’s mere disclosure of more than one
 alternative does not constitute a teaching away from any of these alternatives
 because such disclosure does not criticize, discredit, or otherwise discourage the
 solution claimed….” In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d
 1141, 1146 (Fed. Cir. 2004). See also MPEP § 2123 .
 

 

 
 2141.03 Level of Ordinary Skill in the Art [R-01.2024]

 [Editor Note: This MPEP section is applicable regardless of whether an
 application is examined under the AIA or under pre-AIA law. For applications subject
 to the first inventor to file (FITF) provisions of the AIA, the relevant time is
 "before the effective filing date of the claimed invention". For applications subject
 to pre-AIA 35
 U.S.C. 102 , the relevant time is "at the time of the
 invention". See MPEP § 2150 et seq. Many of the
 court decisions discussed in this section involved applications or patents subject to
 pre-AIA 35
 U.S.C. 102 . These court decisions may be applicable to
 applications and patents subject to AIA 35 U.S.C. 102 but the
 relevant time is before the effective filing date of the claimed invention and not at
 the time of the invention.] 

 I. FACTORS TO CONSIDER IN DETERMINING LEVEL OF ORDINARY SKILL The person of ordinary skill in the art is a hypothetical person who
 is presumed to have known the relevant art at the relevant time. Factors that may be
 considered in determining the level of ordinary skill in the art may include: (A)
 “type of problems encountered in the art;” (B) “prior art solutions to those
 problems;” (C) “rapidity with which innovations are made;” (D) “sophistication of the
 technology; and” (E) “educational level of active workers in the field. In a given
 case, every factor may not be present, and one or more factors may predominate.”
 In re GPAC, 57 F.3d 1573, 1579, 35 USPQ2d 1116, 1121 (Fed. Cir.
 1995); Custom Accessories, Inc. v. Jeffrey-Allan Indus., 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 Int'l Co. v. Teleflex Inc., 550
 U.S. 398, 421, 82 USPQ2d 1385, 1397 (2007). “[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 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. 
 

 The level of disclosure in the specification of the
 application under examination or in relevant references may also be informative of
 the knowledge and skills of a person of ordinary skill in the art. For example, if
 the specification is entirely silent on how a certain step or function is achieved,
 that silence may suggest that figuring out how to achieve that step or function is
 within the ordinary skill in the art, provided that the specification complies with
 35 U.S.C.
 112 . Uber Techs., Inc. v. X One, Inc., 957
 F.3d 1334, 1339, 2020 USPQ2d 10476 (Fed. Cir. 2020) (“The specification of the '593
 patent is entirely silent on how to transmit user locations and maps from a server to
 a user's mobile device, suggesting that a person of ordinary skill in the art was
 more than capable of selecting between the known methods of accomplishing this. The
 '593 patent confirms that its invention, including any necessary plotting, ‘utilizes
 existing platforms and infrastructure’ and does not ‘require development of new cell
 phone or PDA technology, nor do[es it] require development of new cellular
 communication infrastructure.’")
 

 The “hypothetical ‘person having ordinary skill in the art’ to which
 the claimed subject matter pertains would, of necessity have the capability of
 understanding the scientific and engineering principles applicable to the pertinent
 art.” Ex parte Hiyamizu, 10 USPQ2d 1393, 1394 (Bd. Pat. App. &
 Inter. 1988) (The Board disagreed with the examiner’s definition of one of ordinary
 skill in the art (a doctorate level engineer or scientist working at least 40 hours
 per week in semiconductor research or development), finding that the hypothetical
 person is not definable by way of credentials, and that the evidence in the
 application did not support the conclusion that such a person would require a
 doctorate or equivalent knowledge in science or engineering.). 
 

 References which are not prior art may be relied upon to demonstrate
 the level of ordinary skill in the art at or around the relevant time. See
 In re Merck & Co., Inc., 800 F.2d 1091, 1098, 231 USPQ 375,
 380 (Fed. Cir. 1986) (“Evidence of contemporaneous invention is probative of ‘the
 level of knowledge in the art at the time the invention was made.’” (citing
 In re Farrenkopf, 713 F.2d 714, 720, 219 USPQ 1, 6 (Fed. Cir.
 1983))); Ecolochem, Inc. v. S. California Edison Co., 227 F.3d
 1361, 1379, 56 USPQ2d 1065, 1079 (Fed. Cir. 2000) (“The fact of near-simultaneous
 invention, though not determinative of statutory obviousness, is strong evidence of
 what constitutes the level of ordinary skill in the art.” (quoting The Int’l
 Glass Co. v. United States, 408 F.2d 395, 405, 159 USPQ 434, 442 (Ct.
 Cl. 1969))). See also Thomas & Betts Corp. v. Litton Sys.,
 Inc., 720 F.2d 1572, 1580-81, 220 USPQ 1, 7 (Fed. Cir. 1983) (“Thus, the
 [unpublished internal materials], though not technically prior art, were, in effect,
 properly used as indicators of the level of ordinary skill in the art to which the
 invention pertained.”). 
 

 Moreover, references not available as prior art may
 be relevant to establishing “a motivation to combine which is implicit in the
 knowledge of one of ordinary skill in the art.” Nat'l Steel Car, Ltd. v.
 Can. Pac. Ry., Ltd., 357 F.3d 1319, 1337-38, 69 USPQ2d 1641, 1656 (Fed.
 Cir. 2004) (holding that a drawing made by an engineer that was not prior art can,
 nonetheless, “... be used to demonstrate a motivation to combine implicit in the
 knowledge of one of ordinary skill in the art.”).
 

 II. SPECIFYING A PARTICULAR LEVEL OF SKILL IS NOT NECESSARY WHERE THE PRIOR ART
 ITSELF REFLECTS AN APPROPRIATE LEVEL If the only facts of record pertaining to the level of skill in the
 art are found within the prior art of record, the court has held that an invention
 may be held to have been obvious without a specific finding of a particular level of
 skill where the prior art itself reflects an appropriate level. Chore-Time
 Equipment, Inc. v. Cumberland Corp., 713 F.2d 774, 218 USPQ 673 (Fed.
 Cir. 1983). See also Okajima v. Bourdeau, 261 F.3d 1350, 1355, 59
 USPQ2d 1795, 1797 (Fed. Cir. 2001).
 

 III. ASCERTAINING LEVEL OF ORDINARY SKILL IS NECESSARY TO MAINTAIN
 OBJECTIVITY “The importance of resolving the level of ordinary skill in the art
 lies in the necessity of maintaining objectivity in the obviousness inquiry.”
 Ryko Mfg. Co. v. Nu-Star, Inc., 950 F.2d 714, 718, 21 USPQ2d
 1053, 1057 (Fed. Cir. 1991). The examiner must ascertain what would have been obvious
 as of the relevant time to one of ordinary skill in the art, and not to the inventor,
 a judge, a layman, those skilled in remote arts, or to geniuses in the art at hand.
 Environmental Designs, Ltd. v. Union Oil Co., 713 F.2d 693, 218
 USPQ 865 (Fed. Cir. 1983), cert. denied, 464 U.S. 1043 (1984).
 
 

 

 [top] 

 

 

 
 

 
 

 

 

 

 
 
 
 2101-2102-[Reserved] 

 2103-Patent Examination Process 

 2104-Requirements of 35 U.S.C. 101 
 2104.01-Barred by Atomic Energy Act 

 
 

 2105-Patent Eligible Subject Matter — Living Subject Matter 

 2106-Patent Subject Matter Eligibility 
 2106.01-[Reserved] 

 2106.02-[Reserved] 

 2106.03-Eligibility Step 1: The Four Categories of Statutory Subject Matter 

 2106.04-Eligibility Step 2A: Whether a Claim is Directed to a Judicial Exception 
 2106.04(a)-Abstract Ideas 
 2106.04(a)(1)-Examples of Claims That Do Not Recite Abstract Ideas 

 2106.04(a)(2)-Abstract Idea Groupings 

 2106.04(a)(3)-Tentative Abstract Ideas 

 
 

 2106.04(b)-Laws of Nature, Natural Phenomena & Products of Nature 

 2106.04(c)-The Markedly Different Characteristics Analysis 

 2106.04(d)-Integration of a Judicial Exception Into A Practical Application 
 2106.04(d)(1)-Evaluating Improvements in the Functioning of a Computer, or an Improvement to Any Other Technology or Technical Field in
 Step 2A Prong Two 

 2106.04(d)(2)-Particular Treatment and Prophylaxis in Step 2A Prong Two 

 
 

 
 

 2106.05-Eligibility Step 2B: Whether a Claim Amounts to Significantly More 
 2106.05(a)-Improvements to the Functioning of a Computer or To Any Other Technology or Technical Field 

 2106.05(b)-Particular Machine 

 2106.05(c)-Particular Transformation 

 2106.05(d)-Well-Understood, Routine, Conventional Activity 

 2106.05(e)-Other Meaningful Limitations 

 2106.05(f)-Mere Instructions To Apply An Exception 

 2106.05(g)-Insignificant Extra-Solution Activity 

 2106.05(h)-Field of Use and Technological Environment 

 
 

 2106.06-Streamlined Analysis 
 2106.06(a)-Eligibility is Self Evident 

 2106.06(b)-Clear Improvement to a Technology or to Computer Functionality 

 
 

 2106.07-Formulating and Supporting Rejections For Lack Of Subject Matter Eligibility 
 2106.07(a)-Formulating a Rejection For Lack of Subject Matter Eligibility 
 2106.07(a)(1)-Form Paragraphs for use in Lack of Subject Matter Eligibility Rejections 

 
 

 2106.07(b)-Evaluating Applicant’s Response 

 2106.07(c)-Clarifying the Record 

 
 

 
 

 2107-Guidelines for Examination of Applications for Compliance with the Utility Requirement 
 2107.01-General Principles Governing Utility Rejections 

 2107.02-Procedural Considerations Related to Rejections for Lack of Utility 

 2107.03-Special Considerations for Asserted Therapeutic or Pharmacological Utilities 

 
 

 2108-[Reserved] 

 2109-Inventorship 

 2109.01-Joint Inventorship 

 2110-[Reserved] 

 2111-Claim Interpretation; Broadest Reasonable Interpretation 
 2111.01-Plain Meaning 

 2111.02-Effect of Preamble 

 2111.03-Transitional Phrases 

 2111.04-“Adapted to,” “Adapted for,” “Wherein,” “Whereby,” and Contingent Clauses 

 2111.05-Functional and Nonfunctional Descriptive Material 

 
 

 2112-Requirements of Rejection Based on Inherency; Burden of Proof 
 2112.01-Composition, Product, and Apparatus Claims 

 2112.02-Process Claims 

 
 

 2113-Product-by-Process Claims 

 2114-Apparatus and Article Claims — Functional Language 

 2115-Material or Article Worked Upon by Apparatus 

 2116-Novel, Nonobvious Starting Material or End Product 
 2116.01-Novel, Nonobvious Starting Material or End Product 

 
 

 2117-Markush Claims 

 2118-2119-[Reserved] 

 2120-Rejection on Prior Art 
 2120.01-Rejections Under 35 U.S.C. 102(a)(1) and (a)(2) and Pre-AIA 35 U.S.C. 102(a), (b), or (e): Printed Publication or Patent 

 2120.02-Rejections Under 35 U.S.C. 102(a)(1) or Pre-AIA 35 U.S.C. 102(a) or (b): Knowledge by Others, or Public Use, or On Sale 

 
 

 2121-Prior Art; General Level of Operability Required to Make a Prima Facie Case 
 2121.01-Use of Prior Art in Rejections Where Operability is in Question 

 2121.02-Compounds and Compositions — What Constitutes Enabling Prior Art 

 2121.03-Plant Genetics — What Constitutes Enabling Prior Art 

 2121.04-Apparatus and Articles — What Constitutes Enabling Prior Art 

 
 

 2122-Discussion of Utility in the Prior Art 

 2123-Rejection Over Prior Art’s Broad Disclosure Instead of Preferred Embodiments 

 2124-Exception to the Rule That the Reference Must be Prior Art 
 2124.01-Tax Strategies Deemed Within the Prior Art 

 
 

 2125-Drawings as Prior Art 

 2126-Availability of a Document as a “Patent” for Purposes of Rejection Under 35 U.S.C. 102(a) or Pre-AIA 35 U.S.C. 102(a), (b),
 and (d) 
 2126.01-Date of Availability of a Patent as a Reference 

 2126.02-Scope of Reference’s Disclosure Which Can Be Used to Reject Claims When the Reference Is a “Patent” but Not a “Publication” 

 
 

 2127-Domestic and Foreign Patent Applications as Prior Art 

 2128-“Printed Publications” as Prior Art 
 2128.01-Level of Public Accessibility Required 

 2128.02-Date Publication Is Available as a Reference 

 
 

 2129-Admissions as Prior Art 

 2130-[Reserved] 

 2131-Anticipation — Application of 35 U.S.C. 102 
 2131.01-Multiple Reference 35 U.S.C. 102 Rejections 

 2131.02-Genus-Species Situations 

 2131.03-Anticipation of Ranges 

 2131.04-Secondary Considerations 

 2131.05-Nonanalogous or Disparaging Prior Art 

 
 

 2132-Pre-AIA 35 U.S.C. 102(a) 
 2132.01-Overcoming a Pre-AIA 35 U.S.C. 102(a) Rejection based on a Printed Publication or Patent 

 
 

 2133-Pre-AIA 35 U.S.C. 102(b) 
 2133.01-Rejections of Continuation-In-Part (CIP) Applications 

 2133.02-Rejections Based on Publications and Patents 
 2133.02(a)-Overcoming a Pre-AIA 35 U.S.C. 102(b) Rejection Based on a Printed Publication or Patent 

 
 

 2133.03-Rejections Based on “Public Use” or “On Sale” 
 2133.03(a)-“Public Use” 

 2133.03(b)-“On Sale” 

 2133.03(c)-The “Invention” 

 2133.03(d)-“In This Country” 

 2133.03(e)-Permitted Activity; Experimental Use 
 2133.03(e)(1)-Commercial Exploitation 

 2133.03(e)(2)-Intent 

 2133.03(e)(3)-“Completeness” of the Invention 

 2133.03(e)(4)-Factors Indicative of an Experimental Purpose 

 2133.03(e)(5)-Experimentation and Degree of Supervision and Control 

 2133.03(e)(6)-Permitted Experimental Activity and Testing 

 2133.03(e)(7)-Activity of an Independent Third Party Inventor 

 
 

 
 

 
 

 2134-Pre-AIA 35 U.S.C. 102(c) 

 2135-Pre-AIA 35 U.S.C. 102(d) 
 2135.01-The Four Requirements of Pre-AIA 35 U.S.C. 102(d) 

 
 

 2136-Pre-AIA 35 U.S.C. 102(e) 
 2136.01-Status of Unpublished or Published as Redacted U.S. Application as a Reference Under Pre-AIA 35 U.S.C. 102(e) 

 2136.02-Content of the Prior Art Available Against the Claims 

 2136.03-Critical Reference Date 

 2136.04-Different Inventive Entity; Meaning of “By Another” 

 2136.05-Overcoming a Rejection Under Pre-AIA 35 U.S.C. 102(e) 
 2136.05(a)-Antedating a Pre-AIA 35 U.S.C. 102(e) Reference 

 2136.05(b)-Showing The Reference Is Describing An Inventor's Or At Least One Joint Inventor's Own Work 

 
 

 
 

 2137-Pre-AIA 35 U.S.C. 102(f) 
 2137.01-[Reserved] 

 2137.02-[Reserved] 

 
 

 2138-Pre-AIA 35 U.S.C. 102(g) 
 2138.01-Interference Practice 

 2138.02-“The Invention Was Made in This Country” 

 2138.03-“By Another Who Has Not Abandoned, Suppressed, or Concealed It” 

 2138.04-“Conception” 

 2138.05-“Reduction to Practice” 

 2138.06-“Reasonable Diligence” 

 
 

 2139-Rejections Under Pre-AIA 35 U.S.C. 102 
 2139.01-Effective Filing Date of a Claimed Invention Under Pre-AIA 35 U.S.C. 102 

 2139.02-Determining Whether To Apply Pre-AIA 35 U.S.C. 102(a), (b), or (e) 

 2139.03-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 102 

 
 

 2140-[Reserved] 

 2141-Examination Guidelines for Determining Obviousness Under 35 U.S.C. 103 
 2141.01-Scope and Content of the Prior Art 
 2141.01(a)-Analogous and Nonanalogous Art 

 
 

 2141.02-Differences Between Prior Art and Claimed Invention 

 2141.03-Level of Ordinary Skill in the Art 

 
 

 2142-Legal Concept of Prima Facie Obviousness 

 2143-Examples of Basic Requirements of a Prima Facie Case of Obviousness 
 2143.01-Suggestion or Motivation To Modify the References 

 2143.02-Reasonable Expectation of Success Is Required 

 2143.03-All Claim Limitations Must Be Considered 

 
 

 2144-Supporting a Rejection Under 35 U.S.C. 103 
 2144.01-Implicit Disclosure 

 2144.02-Reliance on Scientific Theory 

 2144.03-Reliance on Common Knowledge in the Art or “Well Known” Prior Art 

 2144.04-Legal Precedent as Source of Supporting Rationale 

 2144.05-Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions 

 2144.06-Art Recognized Equivalence for the Same Purpose 

 2144.07-Art Recognized Suitability for an Intended Purpose 

 2144.08-Obviousness of Species When Prior Art Teaches Genus 

 2144.09-Close Structural Similarity Between Chemical Compounds (Homologs, Analogues, Isomers) 

 
 

 2145-Consideration of Applicant’s Rebuttal Arguments and Evidence 

 2146-Pre-AIA 35 U.S.C. 103(c) 
 2146.01-Prior Art Disqualification Under Pre-AIA 35 U.S.C. 103(c) 

 2146.02-Establishing Common Ownership or Joint Research Agreement Under Pre-AIA 35 U.S.C. 103(c) 

 2146.03-Examination Procedure With Respect to Pre-AIA 35 U.S.C. 103(c) 
 2146.03(a)-Provisional Rejection (Obviousness) Under 35 U.S.C. 103(a) Using Provisional Prior Art Under Pre-AIA 35 U.S.C. 102(e) 

 
 

 
 

 2147-Biotechnology Process Applications; Pre-AIA 35 U.S.C. 103(b) 

 2148-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 103 

 2149-[Reserved] 

 2150-Examination Guidelines for 35 U.S.C. 102 and 103 as Amended by the First Inventor To File Provisions of the Leahy-Smith America
 Invents Act 

 2151-Overview of the Changes to 35 U.S.C. 102 and 103 in the AIA 

 2152-Detailed Discussion of AIA 35 U.S.C. 102(a) and (b) 
 2152.01-Effective Filing Date of the Claimed Invention 

 2152.02-Prior Art Under AIA 35 U.S.C. 102(a)(1) (Patented, Described in a Printed Publication, or in Public Use, on Sale, or Otherwise
 Available to the Public) 
 2152.02(a)-Patented 

 2152.02(b)-Described in a Printed Publication 

 2152.02(c)-In Public Use 

 2152.02(d)-On Sale 

 2152.02(e)-Otherwise Available to the Public 

 2152.02(f)-No Requirement of “By Others” 

 
 

 2152.03-Admissions 

 2152.04-The Meaning of “Disclosure” 

 2152.05-Determining Whether To Apply 35 U.S.C. 102(a)(1) or 102(a)(2) 

 2152.06-Overcoming a 35 U.S.C. 102(a)(1) or 102(a)(2) Rejection 

 2152.07-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 102 

 
 

 2153-Prior Art Exceptions Under 35 U.S.C. 102(b)(1) to AIA 35 U.S.C. 102(a)(1) 
 2153.01-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(A) To AIA 35 U.S.C. 102(a)(1) (Grace Period Inventor-Originated Disclosure
 Exception) 
 2153.01(a)-Grace Period Inventor-Originated Disclosure Exception 

 2153.01(b)-[Reserved] 

 
 

 2153.02-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(B) to AIA 35 U.S.C. 102(a)(1) (Inventor-Originated Prior Public Disclosure
 Exception) 

 
 

 2154-Provisions Pertaining to Subject Matter in a U.S. Patent or Application Effectively Filed Before the Effective Filing Date
 of the Claimed Invention 
 2154.01-Prior Art Under AIA 35 U.S.C. 102(a)(2) “U.S. Patent Documents” 
 2154.01(a)-WIPO Published Applications 

 2154.01(b)-Determining When Subject Matter Was Effectively Filed Under AIA 35 U.S.C. 102(d) 

 2154.01(c)-Requirement Of “Names Another Inventor” 

 2154.01(d)-Provisional Rejections Under 35 U.S.C. 102(a)(2); Reference Is a Copending U.S. Patent Application 

 
 

 2154.02-Prior Art Exceptions Under 35 U.S.C. 102(b)(2) to AIA 35 U.S.C. 102(a)(2) 
 2154.02(a)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(A) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Disclosure Exception) 

 2154.02(b)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(B) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Prior Public Disclosure
 Exception) 

 2154.02(c)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(C) to AIA 35 U.S.C. 102(a)(2) (Common Ownership or Obligation of Assignment) 

 
 

 
 

 2155-Use of Affidavits or Declarations Under 37 CFR 1.130 To Overcome Prior Art Rejections 
 2155.01-Showing That the Disclosure Was Made by the Inventor or a Joint Inventor 

 2155.02-Showing That the Subject Matter Disclosed Had Been Previously Publicly Disclosed by the Inventor or a Joint Inventor 

 2155.03-Showing That the Disclosure was Made, or That Subject Matter had Been Previously Publicly Disclosed, by Another Who Obtained
 the Subject Matter Disclosed Directly or Indirectly From the Inventor or a Joint Inventor 

 2155.04-Enablement 

 2155.05-Who May File an Affidavit or Declaration Under 37 CFR 1.130 

 2155.06-Situations in Which an Affidavit or Declaration Is Not Available 

 
 

 2156-Joint Research Agreements 

 2157-Improper Naming of Inventors 

 2158-AIA 35 U.S.C. 103 
 2158.01-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 103 

 
 

 2159-Applicability Date Provisions and Determining Whether an Application Is Subject to the First Inventor To File Provisions of
 the AIA 
 2159.01-Applications Filed Before March 16, 2013 

 2159.02-Applications Filed on or After March 16, 2013 

 2159.03-Applications Subject to the AIA but Also Containing a Claimed Invention Having an Effective Filing Date Before March 16, 2013 

 2159.04-Applicant Statement in Transition Applications Containing a Claimed Invention Having an Effective Filing Date on or After
 March 16, 2013 

 
 

 2160-[Reserved] 

 2161-Three Separate Requirements for Specification Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 
 2161.01-Computer Programming, Computer Implemented Inventions, and 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 
 

 2162-Policy Underlying 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2163-Guidelines for the Examination of Patent Applications Under the 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, first paragraph,
 “Written Description” Requirement 
 2163.01-Support for the Claimed Subject Matter in Disclosure 

 2163.02-Standard for Determining Compliance With the Written Description Requirement 

 2163.03-Typical Circumstances Where Adequate Written Description Issue Arises 

 2163.04-Burden on the Examiner with Regard to the Written Description Requirement 

 2163.05-Changes to the Scope of Claims 

 2163.06-Relationship of Written Description Requirement to New Matter 

 2163.07-Amendments to Application Which Are Supported in the Original Description 
 2163.07(a)-Inherent Function, Theory, or Advantage 

 2163.07(b)-Incorporation by Reference 

 
 

 
 

 2164-The Enablement Requirement 
 2164.01-Test of Enablement 
 2164.01(a)-Undue Experimentation Factors 

 2164.01(b)-How to Make the Claimed Invention 

 2164.01(c)-How to Use the Claimed Invention 

 
 

 2164.02-Working and Prophetic Examples 

 2164.03-Relationship of Predictability of the Art and the Enablement Requirement 

 2164.04-Burden on the Examiner Under the Enablement Requirement 

 2164.05-Determination of Enablement Based on Evidence as a Whole 
 2164.05(a)-Specification Must Be Enabling as of the Filing Date 

 2164.05(b)-Specification Must Be Enabling to Persons Skilled in the Art 

 
 

 2164.06-Quantity of Experimentation 
 2164.06(a)-Examples of Enablement Issues-Missing Information 

 2164.06(b)-Examples of Enablement Issues — Biological and Chemical Cases 

 2164.06(c)-Examples of Enablement Issues – Computer Programming Cases 

 
 

 2164.07-Relationship of Enablement Requirement to Utility Requirement of 35 U.S.C. 101 

 2164.08-Enablement Commensurate in Scope With the Claims 
 2164.08(a)-Single Means Claim 

 2164.08(b)-Inoperative Subject Matter 

 2164.08(c)-Critical Feature Not Claimed 

 
 

 
 

 2165-The Best Mode Requirement 
 2165.01-Considerations Relevant to Best Mode 

 2165.02-Best Mode Requirement Compared to Enablement Requirement 

 2165.03-Requirements for Rejection for Lack of Best Mode 

 2165.04-Examples of Evidence of Concealment 

 
 

 2166-Rejections Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2167-2170-[Reserved] 

 2171-Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2172-Subject Matter Which the Inventor or a Joint Inventor Regards as The Invention 
 2172.01-Unclaimed Essential Subject Matter 

 
 

 2173-Claims Must Particularly Point Out and Distinctly Claim the Invention 
 2173.01-Interpreting the Claims 

 2173.02-Determining Whether Claim Language is Definite 

 2173.03-Correspondence Between Specification and Claims 

 2173.04-Breadth Is Not Indefiniteness 

 2173.05-Specific Topics Related to Issues Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 
 2173.05(a)-New Terminology 

 2173.05(b)-Relative Terminology 

 2173.05(c)-Numerical Ranges and Amounts Limitations 

 2173.05(d)-Exemplary Claim Language (“for example,” “such as”) 

 2173.05(e)-Lack of Antecedent Basis 

 2173.05(f)-Reference to Limitations in Another Claim 

 2173.05(g)-Functional Limitations 

 2173.05(h)-Alternative Limitations 

 2173.05(i)-Negative Limitations 

 2173.05(j)-Old Combination 

 2173.05(k)-Aggregation 

 2173.05(l)-[Reserved] 

 2173.05(m)-Prolix 

 2173.05(n)-Multiplicity 

 2173.05(o)-Double Inclusion 

 2173.05(p)-Claim Directed to Product-By- Process or Product and Process 

 2173.05(q)-“Use” Claims 

 2173.05(r)-Omnibus Claim 

 2173.05(s)-Reference to Figures or Tables 

 2173.05(t)-Chemical Formula 

 2173.05(u)-Trademarks or Trade Names in a Claim 

 2173.05(v)-Mere Function of Machine 

 
 

 2173.06-Practice Compact Prosecution 

 
 

 2174-Relationship Between the Requirements of 35 U.S.C. 112(a) and (b) or Pre-AIA 35 U.S.C. 112, First and Second Paragraphs 

 2175-Form Paragraphs for Use in Rejections Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2176-2180-[Reserved] 

 2181-Identifying and Interpreting a 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph Limitation 

 2182-Search and Identification of the Prior Art 

 2183-Making a Prima Facie Case of Equivalence 

 2184-Determining Whether an Applicant Has Met the Burden of Proving Nonequivalence After a Prima Facie Case Is Made 

 2185-Related Issues Under 35 U.S.C. 112(a) or (b) and Pre-AIA 35 U.S.C. 112, First or Second Paragraphs 

 2186-Relationship to the Doctrine of Equivalents 

 2187-Form Paragraphs for Use Relating to 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph 

 2188-2189-[Reserved] 

 2190-Prosecution Laches and Res Judicata 

 

 

 
 

 
 
 

 
 

 

 
 
 Accessibility 

 Privacy Policy 

 Terms of Use 

 Security 

 Emergencies/Security Alerts 

 Information Quality Guidelines 

 
 

 
 
 Federal Activities Inventory Reform (FAIR) Act 

 Notification and Federal Employee Antidiscrimination and Retaliation (NoFEAR) Act 

 Budget & Performance 

 Freedom of Information Act (FOIA) 

 
 

 
 
 Department of Commerce NoFEAR Act Report 

 Regulations.gov 

 STOP!Fakes.gov 

 Department of Commerce 

 USA.gov 

 
 

 
 
 Strategy Targeting Organized Piracy (STOP!) 

 Careers 

 Site Index 

 Contact Us 

 Submit Feedback 

 
 

 
 This page is owned by Patents.

 Last Modified: 
 
 03/09/2026 20:50:40