Episode 5: Learning to Learn

Episode 5 – Learning to Learn > Uncut conversations > Uncut conversations

• How do people generally diagnose? I mean, it’s really kind of categorization problem, isn’t it? What is categorization, more generally, and how do people do it? Well, before we get there, let me back up a second and give you an idea as to how we got into this mess.
• What emerged even back then in the late ’70s was that in fact the general skill really wasn’t very general.
• At another level, it was too specific because success on one problem had very little to do with success on the next problem.
• That led to thinking about, well, maybe this isn’t the way to characterize it at all.
• I think, for me personally, the breakthrough was to work with people at McMaster who were really into what is called concept formation or categorization.
• I think, has a long history in psychology.
• I think it’s fair to say that, initially, the thinking was that there must be some implicit rules that governed each category, but a moment’s reflection on, say, a beanbag chair tells you that the implicit rules of chairs are unlikely to be necessary and sufficient.
• So what makes a chair a chair is normally, someone would think, four legs, maybe wooden chair, but that sort of rule might not be all encompassing.
• The two more prevalent views-one is that, essentially, we average our experiences into a prototype, and that prototypes are distinguished as having more of the features of the category and fewer than the features of other categories.
• Glenn Regehr actually has a very nice example of that.
• He says, “Suppose you grow up in the Yukon, and all you see is huskies. How many Chihuahuas do you have to see before you recognize a Chihuahua as a dog?” The answer is one.
• I have a talk about this whole issue of medical diagnosis, and one of the key features and the one that grabs the audience inevitably is the video of my year-and-a-half-old daughter where we show her playing a Fisher-Price toy with dogs and cats, and B.F. Skinner would be happy as can be because what she’s learned is that if she puts that thing in that slot, then Mommy gives her popsicle and tells her how wonderful she is.
• She can’t say, “Dog.” It is implausible that she would have a rule for “Dog.” Yes.
• Obviously, the mystery would be what exactly is that similarity matching? How does that come about? I think then you can invoke more fundamental models of the nature of memory, which is associationist or connectionist, which basically says that we are somehow, in a very rapid and unconscious way, matched in individual attributes and seeking connections that way.
• That’s far-too-basic science and psychology for me to play with, but that’s, I think, a pretty decent model.
• What about your doctors? When we go from everyday classification or categories, like dogs and cats and tables and chairs, and you only need just a few exemplars to be able to get the job done, do docs work the same way? If you’re learning about skin lesions and mental disorders or more complex types of categories, is it just take a few exemplars there as well? Well, clearly, medical diagnosis is a bit more complex in part because the-yes, for skin lesions, we can imagine a picture that’s kind of like looking at a picture of a dog.
• Clearly, what differentiates the expert from the novice is not how many hypotheses or how early, but what are the hypotheses, and expertise resides entirely in generating better hypotheses.
• Exemplar models are very powerful way of thinking about that-that, essentially, prior experience is available to you.
• One of the-a couple games I play with audiences quite often, one is to ask them, “How long after you graduated before you thought you were competent?” Now to the average person on the street, you think that would be ruled out of order from the outset-they’re competent when we graduated them, aren’t they? Right.
• Yet there’s no textbook that has a chapter on how to diagnose “Sick”.
• There are number of conditions that run the pages that are all considered sick conditions, but a very recent study actually just published this year showed that if you turn to the emergency doc and say, “Is this one sick or not,” and he makes a judgment in seconds, and that has about an 85-percent accuracy in terms of predicting whether ultimately, when they get to the wards, they end up with a very serious diagnosis.
• I mean, that’s what they do in medical school, isn’t it, is learn the rules? They’re very careful and deliberative in coming up with these diagnoses.
• I think in every clinical encounter, there’s really two fairly distinct phases: the initial phase of hypothesis generation-it’s so effortless; it just seems to be too easy-and then a second confirmation phase where they go back to the rules, the 29 causes of anemia, the signs and symptoms of pernicious anemia, and so forth, just to confirm that that’s what they’re dealing with.
• People sort of think you’re not really doing your work; you’re not working hard enough.
• He’s written a book that I think many people know-it was on “The New York Times” bestseller list for at least a year-called “Thinking, Fast and Slow.” His claim is just that: that essentially fast thinking, system-one thinking, leads to errors and that we should be cautioning people, doctors, and everyone else to be more slow, rational, thoughtful, and that that would reduce the errors that happen in human judgments.
• I think we should wait just a second for that high pitch.
• It seems-I agree, and in fact I think it’s safe to say that the majority view is that the slow process is going to be ultimately higher benefit in the long run, but that’s against the evidence.
• It seems, at least given his preliminary work, that we’re not very good at it-that is, we don’t seem to be very good at assessing how well we can do various things.
• Kevin should be here to speak to it, but I think I can pretty well paraphrase what Kevin would say.
• If I think of all the people who are watching this video, I’m going to ask them all a simple question.
• He said, “How can I know what I don’t know when I don’t know what I don’t know?” Right.
• So how do they improve? As an expert, you mentioned that we-going slow doesn’t necessarily help, being deliberative, and there is this compounded issue of self-assessment, that we often don’t know how good we’re actually doing in any given case.
• What does that mean for improving practice? How do we get better? How do we-the goal of this course that we’re taking is called “The Science of Everyday Thinking.” Given your experience in the field of expertise and in medicine, how do we improve everyday thinking? You improve by knowing more.
• This course wouldn’t exist if we didn’t think that there are some-that being explicit about everyday thinking and the traps in everyday thinking wouldn’t help people think better.
• At some level that’s true, but that’s generally locked in to what’s been called general problem-solving strategies, which are not very powerful.
• Very clearly, the single best predictor of how good you are is how much you know about the domain, not what problem-solving skills you bring to bear on it.
• So then would you suggest, in getting more experience, in gaining and kind of accumulating knowledge, is it just a matter of studying the domain more, of getting more experience? If I’m a novice diagnostician, in order to become an expert, in order to become an expert in the true sense, is it just a matter of working hard and studying the rules and getting as much exposure to a wide variety of examples within that domain? Yes, we can, but we can do better than that.
• The idea of transfer, which is being able to take knowledge that you’ve learned in one context and apply it to another: one, it doesn’t happen at all as easily as we think it does; but, two, psychologists would devise strategies to make that happen better.
• I think this is moving much more into the instructional educational psychology end of things.
• There are things we can do to very much enhance the efficiency with which you acquire the knowledge you need to get the job done as a diagnostician or as a human.