FAQ on expertise

Professionally, I research and train expertise. Somewhat less professionally I write about it on Substack. I typically work in domains like medicine, military tactics, law enforcement, and petrochemical safety, but I also explore implications for sports, music, video games, and recently mathematics. Because of this, I receive a lot of questions about the nature of expertise which I thought could be cleared up with a FAQ.It is important to note my background. I come from a tradition called Naturalistic Decision Making (NDM) which puts more emphasis on decision-making, cognition and the ability to adapt to novel circumstances, and less focus on memorization, repetition, and motor skills. It also means that I approach cognition in a certain way that other schools of thought may disagree with. I will do my best to explain my answers, but other researchers may disagree with me, and that is OK. The science is not completely settled.1With that caveats out of the way, here are some frequently asked questions.What is expertise?How do experts do it? What makes them special?What is meant by pattern recognition?Is expertise gut instinct?Should I trust my gut instinct?How do you study expertise?How do you train expertise?What about Deliberate Practice?What about the Constraints Led Approach?Why study expertise instead of rationality?Is expertise about generalizing rules? How are experts so adaptive?What are some resources for learning about expertise?Expertise can be defined in terms of (1) absolute performance on a task, (2) performance relative to others, or (3) the underlying psychology. Which definition you use depends on what you are trying to accomplish. Because I am interested in the psychology of expertise, I tend to focus on that third definition, and think of expertise as the natural development of human capacity.One way to think of the psychology of expertise is that is an ability to see and act on a problem and its solution quickly and effectively by relying on experience. Or to be more pithy; it is an uncommon common sense.Consider what it is like to make a left hand turn at a busy intersection (or a right hand turn if you live in a country that drives on the wrong side of the road).

You must decide when to start slowing downhow fast to slow down (which requires deciding how much to press the peddle)whether to come to a complete stophow far to pull into the middle of the intersectionthe moment to turnwhich lane to turn intowhether to use your turn signal (yes)etc. Then, ON TOP of all that, you have to pay attention to where you are in your lanethe cars next to youthe oncoming traffic, and whether they are slowing down or speeding uppedestrians that might be crossing the streetcars behind you that might rear end youthe color of the light signaletc.That is incredibly complex! Yet, for someone with years of experience, making a left-hand turn doesn’t feel like a series of decisions requiring deliberation; it feels like common sense. Like you are just doing the obvious thing that you are supposed to do in that situation.Well, that’s expertise. Experts often report that they don’t make decisions and are just following procedure. They have seen the same situational patterns so many times that they are able to quickly understand and know what to do, just like common sense. Expertise is not about knowing lots of explicit facts, but instead defined by what we call tacit knowledge; that is knowledge that is hard to articulate because it is so implicit to how we move about in the world.Tacit knowledge is all the things that sometimes get called intuition; our ability to make subtle distinctions, understand causal relations, notice anomalies, and recognize patterns. Because tacit knowledge is hard to articulate, we sometimes use the phrase deep expertise to differentiate experts with tacit knowledge from people who merely know a lot of stuff (e.g., academic expertise).Why is this focus on tacit knowledge so important for understanding expertise? Because if the relevant knowledge were easily articulated, then you could just turn it into a series of protocols and procedures which you could follow. In other words, if performance depends on explicit knowledge, then no expertise is required as you could just follow a checklist. It is precisely the fact that some types of knowledge are hard (or impossible) to articulate which makes expertise necessary and possible.A framework for types of tacit knowledge. SourceFor example, how would you describe to someone with no experience how fast to slow down at a red light? Or how to anticipate whether you will get T-boned if you turn now rather than waiting for the next car?

Or consider how you must anticipate cars changing lanes even though not everyone uses their blinker. Are these things even articulable? Or do you just get a feel for it? That feel is what we call tacit knowledge because of how difficult (or impossible) it is to articulate.Patterns can be anything which triggers recognition. A Chess Grand Master might recognize a move their opponent is trying to make; a driver might recognize the signs that someone else on the road is driving angry; a football player might recognize the play the opponents are about to try.The patterns we notice are often hard to articulate which makes them a type of tacit knowledge, and often the most important type of tacit knowledge. Pattern recognition is central to the Recognition Primed Decision-Making model which details how experts act in the real world, describing how recognition helps us know what to expect, what other cues to look for, what goals to pursue, and what actions to take. It is also central to the Data-Frame Theory of Sensemaking, another important theory describing how experts operate in real world environments when the full story is missing.However, it is important to note that one of the defining characteristics of experts is their ability to adapt, and this often requires recognizing novel patterns they have never seen before, and figuring out which patterns (of the billions of potential patterns) are actually relevant. There is a circularity here that is hard to explain (how could you recognize something you have never seen before?) but which is central to understanding expertise.This is a common misconception. Neither intuition or tacit knowledge can be boiled down to gut instinct, as both can (and often do) involve significant thinking and deliberation. For example, a doctor trying to figure out the diagnosis for a tricky patient is going to be relying heavily on every faculty they have in order to make sense of complicated symptoms; a firefighter putting out a fire might mentally simulate what will happen if they attack the fire from a certain angle; and an experienced driver will consider how their actions will be perceived by other drivers. Much of this happens quickly and in ways that are hard to articulate, but it is not just gut instinct.However, that isn’t to say gut instinct never plays a role. Gary Klein likes to tell a story of a firefighter who got a bad feeling and ordered everyone out of a burning building. When asked to justify his decision, he had no reason - just a feeling.

Moments later when they were out of the building, it collapsed behind them. The team narrowly avoided dying thanks to this gut instinct decision.Because of this event, the firefighter believed he had ESP as he couldn’t explain where his bad feeling came from. It took Gary interviewing him before he recognized that it wasn’t ESP, but rather he had unconsciously picked up on some things; the fire was too hot and too quiet, and the hose water less effective than he thought it should be. All these anomalies helped him to realize there was something about the situation he did not understand, and that is why he wanted the team out of the house. It was not magic, just subconscious pattern matching (or anomaly detection). (For similar stories, check out Gary’s book Sources of Power which is a very fun read)Stories like that of this firefighter do happen. We have gut instincts all the time about people, decisions, and situations. And sometimes those instincts are justified. But other times that instinct can lead us astray. The lesson from expertise research isn’t that gut instinct is rational and trustworthy - the lesson is that there is no substitute for deep familiarity which allows us to detect patterns even when we are not always aware of it. Gut instinct, like all tacit knowledge, is shaped by experience and needs to be trained.Gut instinct is not magic. It is just a sign that you are picking up on something that is hard to articulate. That hard to articulate thing might be valid, or it might not be. Whether you decide to trust your gut instinct depends on how much experience you have, the reliability of the cues you are using, and the consequences of acting or not acting.For example, you might have enough experience with a close friend that you can recognize the signs and patterns that they have had a bad day, and have an instinct that they are upset. Yet, you still might occasionally misread the situation, as emotional cues are not one-to-one like psychology textbooks sometimes make it seem. So rather than jumping to conclusions, you might act cautiously and probe to see if your intuition is right, as assuming you know how they feel could blowback in your face.In an ideal world, you would pay always close attention to your gut instinct, and over time get a sense for how accurate it is and would become better at discerning what underlies the instinct. In that way, logic and intuition would be working together to improve each other.

But if you are googling this question, then you probably haven’t spent years building up your gut instinct in this way.Overall, a gut instinct says there is something you are picking up on that you are not consciously aware of. I would pay attention to that gut instinct as a valid source of information, but also I would try to figure out what underlies that instinct as it may not be something you would care about if you reflected on it.In the domains I study, it is rarely possible to go out into the field and observe what experts do, but most who research expertise are skeptical that a lab environment offers enough fidelity to really understand expertise. The real world is complex in ways that are hard to capture in a controlled laboratory setting. Since expertise is fundamentally about adapting to context, the sterility of a lab setting defeats much of the purpose.Because of this, the major approach for studying expertise is an interview technique called Cognitive Task Analysis, and more specifically the Critical Decision Method in which we ask experts to walk us through an event, minute by minute, detailing what they noticed and when. Sometimes we pair this interview technique with a recording of a real event to improve memory, and other times we will have the expert go through a scenario that we created. It is important to note that we never ask experts, “Why did you do that?” and instead we ask what they noticed. This is because experts themselves are not trustworthy witnesses to their own cognition. They often confabulate an explanation that doesn’t reflect their true reasoning process (e.g., I have ESP). Instead we ask them to focus on what they noticed as that helps to reveal the cues they are acting on (e.g., the anomalies the firefighter picked up on which led him to order his team out of the house before it collapsed). Additionally, we like to ask them what a novice would get wrong, as that helps to identify the moments that are most difficult and require the most tacit knowledge.For more on how to study expertise, I recommend the book Working Minds: A Practitioner’s Guide to Cognitive Task Analysis.Since expertise is so dependent on pattern matching, there is no real substitute for experience. You must learn what to pay attention to, and how reliable those cues are.