Jurors are often instructed to become time travelers and reconstruct what may have happened "back when."1 The courts have instructed that for jurors facing issues of obviousness in a patent trial, the decision regarding whether or not an alleged invention was new and non-obvious at the time of the invention should be predicated on the choices that a person of ordinary skill in the art (POSA) would have made in the past.2

Not surprisingly, jurors are often skeptical about the relevance and credibility of this hypothetical exercise. As a result, in preparing for trial, the patent trial lawyer and her expert face the challenge of adding meat—in the form of credible and reality based details—on the bones of this amorphous skeleton by showing what would have been the thoughts and choices of this fictitious mind.

Evolution of POSA

As early as 1850,3 in the seminal case of Hotchkiss v. Greenwood, the Supreme Court held invalid a doorknob patent for "an absence of that degree of skill and ingenuity which constitute essential elements of every invention."4 The benchmark for that "degree of skill and ingenuity" was none other than the "ordinary mechanic."

Congress eventually codified the non-obviousness requirement of patentability in the Patent Act of 1952, introducing the phrase "person having ordinary skill in the art" into modern parlance.5 However, the Legislature declined to define the term, leaving it to the judiciary to strike a balance between the competing interests of promoting technological innovation and stifling undeserving monopolies.

Accordingly, the Supreme Court laid out the framework for analyzing obviousness in Graham v. John Deere Co., holding that "[u]nder [the Patent Act of 1952], the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the pertinent art resolved."6

Since Graham, the U.S. Court of Appeals for the Federal Circuit has attempted to clarify what it means to be a POSA. One well-settled presumption is that a POSA is knowledgeable of all the art within his field.7 Another, more ambiguous presumption, is that the POSA is "to be one who thinks along the line of conventional wisdom in the art and is not one who undertakes to innovate, whether by patient, and often expensive, systematic research or by extraordinary insights."8

Commentators have contended that this presumption paints the POSA as devoid of creativity or intuition.9 In an effort to provide clarification, the Supreme Court revisited the issue in KSR Int'l Co. v. Teleflex explaining that: "[a] person of ordinary skill is also a person of ordinary creativity, not an automaton."10

The difference between what is an ordinary, safe, predictable, pedestrian choice and an extraordinary, risky, unpredictable, creative decision is vague territory left to jurors to navigate. To help jurors distinguish the "normal or ordinary" from the "unusual or extraordinary," it seems that identifying a set of decision-making influences, practices, biases or tendencies of the POSA might be useful.

Much like the Georgia Pacific factors, which have become widely accepted as the foundation for the hypothetical "what if" reasonable royalty analyses,11 an effort to identify such a matrix of decision-making factors might provide a useful guide to jurors faced with the challenge of coming to an understanding of what, why and how a POSA would have made his or her choices at the time of the invention.

The Mind of the POSA

Much has been written recently regarding the process and factors influencing ordinary or typical decision-making.12 When trying to understand the mind and choices of the POSA, it seems both fair and useful to consider what we have learned generally about heuristics, i.e., current psychological theories of decision making. Five biases are particularly significant when trying to explain the process of POSA decision-making:

1. Diagnosis Bias. As we are introduced to new information regarding a person or situation, our mind filters that new information to avoid evidence that contradicts our initial characterization. Consider the "first impression" that a POSA is likely to have formed when he first encounters the challenges and circumstances of solving the problem that resulted in the invention at issue. For example, describing the POSA's first impression might provide useful insight when discussing the identification of a "lead compound" in the pharmaceutical context. Keep in mind that a POSA's first impression may also be his last.

2. Negativity Bias. "The brain of humans and other animals contain a mechanism that is designed to give priority to bad news….threats are privileged above opportunities."13 Or, more vividly, "a single cockroach will completely wreck the appeal of a bowl of cherries, but a cherry will do nothing at all for a bowl of cockroaches."14

All data points are not of equal value and bad information seems to carry more influence than good information. The ordinary scientist is not likely to value all data equally. The most apparent application of this comes when the prior art "teaches away" from certain of the choices or options.15 The POSA may be more likely to build a hierarchy of options in which bad news in the prior art is going to have more impact than good news.

3. Loss Aversion Bias. Loss aversion bias refers to the natural human tendency to fear losses more heavily than we relish potential gains.16 As the POSA weighs his or her options, the cost/benefit of each will impact which direction he favors. Real world factors, whether political, social, economic or competitive, may contribute to the risk/reward equation influencing the POSA's decision-making. In choosing a path, the POSA will gravitate toward one that minimizes risk, even if this means sacrificing potential gain.

4. Certainty Bias. Certainty bias refers to the natural human tendency to avoid internal discord or dissonance. "It feels good to be certain. Confidence is comforting."17 Decision-makers will ordinarily take the easier route to decisions and replace hard questions with easier ones.

The harder, the less traveled, the more complex the choice, the less likely the ordinary problem solver will pursue it.

5. Hindsight Bias. In the context of obviousness, jurors and experts are instructed to imagine a hypothetical world where the disputed invention does not yet exist and asked to forget the existence of a known invention. However, as one commentator noted, "[o]verestimating the likelihood of a known invention occurring will tend to make the invention appear obvious."18

The Federal Circuit has suggested several methods to combat this hindsight bias. For example, in Mintz v. Dietz & Watson,19 the Federal Circuit reiterated one of the court's most frequently cited tactics against hindsight bias, the teaching-suggestion-motivation (TSM) test. To prevent hindsight and because many inventions are combinations of known things, the TSM test requires a showing that there was a motivation to combine known elements of a claimed invention as a predicate to an obviousness finding. Though not the exclusive test for obviousness, the TSM test is still considered a useful tool.20

Eliminating the effect of hindsight bias becomes trickier when the disclosure is implicit. Relying on the state of the art at the time may provide the contemporaneous support that the implication was, in fact, understood. Absent such contemporaneous evidence, addressing hindsight bias presents a new challenge. A successful narrative must isolate the how and why the POSA makes the "obvious" choice.

Crafting, Telling, Showing

The challenge of crafting a credible and engaging narrative exploring the problem solving of the hypothetical POSA is not easily accomplished. Like any good narrative, it takes a well-formed thematic plot carried by an interesting and well-developed "hero" who faces and overcomes conflict.21

The development of the central player in the story finds little guidance in the case law. While the courts have suggested that it is important to establish the POSA's "credentials," there has been far less insight into the evidence and its application to answer what, how and why the POSA would make the choices he does. Of course, courts have helped a bit by identifying what cannot be attributed to the POSA—no extraordinary choices and no benefit of hindsight.22 But defining the decision-making factors that would provide clear and convincing23 support regarding the choices of the POSA remain amorphous at best.24

To help answer the questions of the what, how and why of the POSA's decision-making, it seems fair to consider and craft a story that examines human decision-making habits and biases and fit the particularized facts into that framework. The POSA is not an empty vessel into which prior art is dumped and decisions emerge. Instead, he or she possesses the characteristics of the ordinary scientist subject to the pushes and pulls that would likely affect a typical scientist working in a similar environment under similar pressures at the time.

Communicating this to jurors requires an explanation that does not simply provide opinions and conclusions about the choices being made but creates a relatable character with whom jurors can identify or even sympathize. To set the scene, it is often helpful to create a visual image to help carry the description of events.

Your expert becomes a historian of innovation. He takes the jurors back in time to guide them through the journey that the POSA most likely would have traveled. Explaining the choices and the hierarchy and the reasons that the inventive option was or was not on the list and its relative priority on the list becomes your expert's critical contribution.

The expert's teaching of the POSA's journey provides a much more engaging, vivid, memorable and credible basis for the jurors' resolution of the question of whether or not an invention was new and non-obvious. Bringing the hypothetical POSA to life with data-based, reliable decision-making insights will engage the jury and equip them with the tools to make their determination of obviousness.


1. See Gregory N. Mandel, "Patently Non-obvious: Empirical Demonstration That Hindsight Bias Renders Patent Decisions Irrational," 67 Ohio St. L.J. 1391, 1399-1400 (2006).

2. In re Kahn, 441 F.3d 977, 985 (Fed. Cir. 2006). See also, The National Jury Instruction Project, Model Patent Jury Instructions, June 17, 2009.

3. See Hotchkiss v. Greenwood, 52 U.S. 248, 13 L. Ed. 683 (1850).

4. Id. at 267.

5. Patent Act of 1952, Pub. L. No. 82-593, 66 Stat. 792, 798 (1952).

6. 383 U.S. 1, 17 (1966).

7. See id. at 36. Mast, Foos & Co. v. Stover Mfg. Co., 177 U.S. 485, 20 S.Ct. 708, 44 L.Ed. 856 (1900)). See also In re Carlson, 983 F.2d 1032, 1038 (Fed. Cir. 1992).

8. Standard Oil Co. v. Am. Cyanamid Co., 774 F.2d 448, 454 (Fed. Cir. 1985).

9. See Daralyn J. Durie and Mark A. Lemley, "A Realistic Approach to the Obviousness of Inventions," 50 Wm. & Mary L. Rev. 989, 1001 (2008).

10. KSR Int'l Co. v. Teleflex, 550 U.S. 398, 420-21 (2007).

11. See John C. Jarosz, Michael J. Chapman, "The Hypothetical Negotiation and Reasonable Royalty Damages: The Tail Wagging the Dog," 16 Stan. Tech. L. Rev. 769, 779 (2013).

12. See, e.g., "Thinking Fast and Slow," Daniel Kahneman (2011); "How We Decide," Jonah Lehrer (2010); "Why We Make Mistakes," Joseph T. Hallinan (2009); "Sway," Ori Brafman and Rom Brafman (2008).

13. Kahneman at 301.

14. Kahneman at 302.

15. See, e.g., Kinetic Concepts, Inc. v. Smith & Nephew, 688 F.3d 1342, 1369 (Fed. Cir. 2012); Daiichi Sankyo Co. v. Matrix Labs., 619 F.3d 1346, 1353-54 (Fed. Cir. 2010).

16. Kahneman at 302-04.

17. Lehrer at 210.

18. See Mandel, 67 Ohio St. L.J. 1391, 1404 (2006).

19. 679 F.3d 1372 (Fed. Cir. 2012).

20. KSR Int'l Co. v. Teleflex, 550 U.S. 398, 419, 127 S. Ct. 1727, 1741, 167 L. Ed. 2d 705 (2007).

21. See, e.g., "Storytelling for Lawyers," Jonathan Van Patten, University of South Dakota School of Law, January, 2012 at FN 15.

22. See Joseph Scott Miller, "Remixing Obviousness," 16 Tex. Intell. Prop. L.J. 237, 243 (2008).

23. See Procter & Gamble Co. v. Teva Pharm. USA, 566 F.3d 989, 994 (Fed. Cir. 2009).

24. Joseph P. Meara, Ph.D., "Just Who Is the Person Having Ordinary Skill in the Art? Patent Law's Mysterious Personage," 77 Wash. L. Rev. 267 (2002).

Colleen Tracy James is a partner in Mayer Brown's New York office. Daniel Cooper is president of LitStrat Inc., a jury research and litigation consulting firm based in New York City. Jimmy Zhou, an associate in Mayer Brown's New York office, contributed to this article.

Reprinted with permission from the January 5, 2015 edition of the New York Law Journal © 2015 ALM Properties, Inc. All rights reserved. Further duplication without permission is prohibited.