In a world where uncertainty is the norm, “being curious” is one of the ways to hedge volatility in our professional and personal life. By developing and maintaining a state of curiosity in whatever we do, we have a good chance of leading a productive life. The author of this book, Ian Leslie, is a journalist and it should not come as a surprise that this book’s content is essentially “annotating a set of articles and books on curiosity”. The book is a little longer than a blog post / newspaper article and falls short of a well researched book.

We all kind of intuitively know that real learning comes from being curious. Does one need to read a book to know about it? Not really, if you understand that curiosity is vulnerable to benign neglect, if you truly understand what feeds curiosity and what starves it. Unless we are consciously aware of it, our mind might take us in a direction where we are comfortable with the status quo. The more we can identify the factors that keep us in a “curious state”, the better we are, at being in one, or at least in making an effort to get in to that state. This book give visuals/metaphors/examples that gives us some idea of what “others” have talked / written / experienced about curiosity.

Firstly a few terms about curiosity itself. Broadly there are two kinds of curiosities, First is the diversive curiosity , a restless desire for new and next. The other kind is epistemic curiosity, a more disciplined and effortful inquiry, “keep traveling even when the road is bumpy” kind of curiosity. The Googles/wikis/MOOCs of the world whet our diversive curiosity. But that alone is not enough. From time to time, we need to get down and immerse ourselves to get a deeper understanding of stuff around us. If we are forever in the state of diversive curiosity, our capacity for the slow, difficult and frustrating process of gathering knowledge i.e. epistemic curiosity, may be deteriorating.

The author uses Isaiah Berlin’s metaphor of Hedgehog vs. Fox and says that we must be “Foxhogs”. Foxhogs combine the traits of a hedgehog (who has a substantial expertise in something) and a fox ( who is aware of things happening in a ton of other areas). Curious learners go deep and they go wide. Here is a nice visual that captures the traits of a “Foxhog”


Typically they say a startup with 2 or three founders is ideal. I guess the reason might be that atleast the team as a whole, satisfies “foxhog” criterion. Wozniak was a hedgehox and Steve Jobs was a fox, their combination catapulted Apple from a garage startup to what it is today. Alexander Arguelles (I can speak 50 languages) is another foxhog. Charles Darwin, Charlie Munger, Nate Silver are all “foxhogs” who have developed T shaped skillsets.

Tracing the history of curiosity, the author says that, irrespective of the time period you analyze, there has always been a debate between Diversive vs. Epistemic curiosity. In today’s digital world too, with the onslaught of social media and ever increasing attention seeking tools, how does one draw a line between Diversive and Epistemic curiosity appetites? One of the consequences of “knowledge available at a mouse click” is that it robs you of the “desirable difficulty” that is essential for learning. “Slow to learn and slow to forget” is becoming difficult as Internet provides you instant solutions making our learning in to, “easy to learn and easy to forget” activity. Google gives answers to anything that  you question but it won’t tell you what questions to ask. Widening information access does not mean curiosity levels have increased. Ratchet effect is an example of this phenomenon.

Via Omniscience bias:

James Evans, a sociologist at the University of Chicago, assembled a database of 34 million scholarly articles published between 1945 and 2005. He analysed the citations included in the articles to see if patterns of research have changed as journals shifted from print to online. His working assumption was that he would find a more diverse set of citations, as scholars used the web to broaden the scope of their research. Instead, he found that as journals moved online, scholars actually cited fewer articles than they had before. A broadening of available information had led to “a narrowing of science and scholarship”. Explaining his finding, Evans noted that Google has a ratchet effect, making popular articles even more popular, thus quickly establishing and reinforcing a consensus about what’s important and what isn’t. Furthermore, the efficiency of hyperlinks means researchers bypass many of the “marginally related articles” print researchers would routinely stumble upon as they flipped the pages of a printed journal or book. Online research is faster and more predictable than library research, but precisely because of this it can have the effect of shrinking the scope of investigation.

The book makes a strong argument against the ideas propagated by people like Ken Robinson, Sugata Mitra, who claim that knowledge is obsolete, self-directed learning is the only way to educate a child, banishing memorizing stuff from syllabus is important etc. In the late nineteenth and twentieth centuries, a series of thinkers and educators founded “progressive” schools, the core principle of which was the teachers must not get in the way of the child’s innate love of discovery. Are these observations based on evidence? The author cites a lot of empirical research findings and dispels each of the following myths:

  • Myth 1 : Children don’t need teachers to instruct them
  • Myth2 : Fact kills creativity
  • Myth3 : Schools should teach thinking skills instead of knowledge

The last past of the chapter gives a few suggestions to the readers that enable them to be in a “curious state”. Most of them are very obvious but I guess the anecdotes and stories that go along with the suggestions helps one to be more cognizant about them. Here are two of the examples from one of the sections :

International Boring Conference

The Boring Conference is a one-day celebration of the mundane, the ordinary, the obvious and the overlooked – subjects often considered trivial and pointless, but when examined more closely reveal themselves to be deeply fascinating. How often do we pause and look at mundane stuff ?

Georges Perec(Question your tea-spoons)

Perec urges the reader to pay attention not only to the extraordinary but to — as he terms it— the infraordinary, or what happens when nothing happens. We must learn to pay attention to “the daily,” “the habitual”: What we need to question is bricks, concrete, glass, our table manners, our utensils, our tools, the way we spend our time, our rhythms. To question that which seems to have ceased forever to astonish us. We live, true, we breathe, true; we walk, we open doors, we go down staircases, we sit at a table in order to eat, we lie down on a bed to go to sleep. How? Where? When? Why? Describe your street. Describe another street. Compare.Make an inventory of your pockets, of your bag. Ask yourself about the provenance, the use, what will become of each of the objects you take out. Question your tea-spoons.

The book ends with a quote by T.H.White

“The best thing for being sad," replied Merlin, beginning to puff and blow, "is to learn something. That’s the only thing that never fails. You may grow old and trembling in your anatomies, you may lie awake at night listening to the disorder of your veins, you may miss your only love, you may see the world about you devastated by evil lunatics, or know your honour trampled in the sewers of baser minds. There is only one thing for it then — to learn. Learn why the world wags and what wags it. That is the only thing which the mind can never exhaust, never alienate, never be tortured by, never fear or distrust, and never dream of regretting. Learning is the only thing for you. Look what a lot of things there are to learn.”



This book is mainly targeted at high school / college kids who feel their learning efforts are not paying off, teachers who are on the look out for effective instruction techniques, parents who are concerned with their child’s academic results and want to do something about it.

The author of the book, Dr. Barbara Oakley, has an interesting background. She served in the US army as a language translator before transitioning to academia. She is now a professor of engineering at Oakland University in Rochester, Michigan. In her book, she admits that she had to completely retool her mind. A person who was basically in to artsy kind of work had to read hard sciences to get a PhD and do research. Needless to say the transition was a frustrating experience.  One of her research areas is neuroscience where she explores effective human learning techniques. The author claims that her book is essentially meant to demystify some of the common notions that we all have about learning.

This book is  written in “personal journal” format,i.e. with images, anecdotes, stories etc. It is basically a collection of findings that are scattered in various places such as academic papers, blogs, pop science books. So, this book does the job of an “aggregator” , ,much like a Google search, except that the results are supplemented with comments and visuals.

Some of the collated findings mentioned in the book are  :

1) Focused vs.. Diffused mode of thinking : Tons of books have already been written on this subject. The book provides a  visual to remind the reader the basic idea behind it.


In the game “pinball,” a ball, which represents a thought, shoots up from the spring-loaded plunger to bounce randomly against rows of rubber bumpers. These two pinball machines represent focused (left) and diffuse (right) ways of thinking. The focused approach relates to intense concentration on a specific problem or concept. But while in  focused mode , sometimes you inadvertently find yourself focusing intently and trying to solve a problem using erroneous thoughts that are in a different place in the brain from the “solution” thoughts you need to actually need to solve the problem. As an example of this, note the upper “thought” that your pinball first bounces around in on the left-hand image. It is very far away and completely unconnected from the lower pattern of thought in the same brain. You can see how part of the upper thought seems to have an underlying broad path. This is because you’ve thought something similar to that thought before. The lower thought is a new thought— it doesn’t have that underlying broad pattern. The diffuse approach on the right often involves a big-picture perspective. This thinking mode is useful when you are learning something new. As you can see , the diffuse mode doesn’t allow you to focus tightly and intently to solve a specific problem— but it can allow you to get closer to where that solution lies because you’re able to travel much farther before running into another bumper.

2)  Spaced repetition : This idea has lead a massive research area in the field of cognitive psychology. The book nails it with the following visual :


Learning well means allowing time to pass between focused learning sessions , so the neural patterns have time to solidify properly. It’s like allowing time for the mortar to dry when you are building a brick wall, as shown on the left. Trying to learn everything in a few cram sessions doesn’t allow time for neural structures to become consolidated in your long-term memory— the result is a jumbled pile of bricks like those on the right.

3) Limited short term memory :
Experiments have shown that you can at max hold 4 items in your working memory. This means the key to making sense of stuff lies in effective storage and retrieval of concepts/ideas from your long term memory than trying to cram everything in to working memory(which will anyway vanish quickly)

4) Chunking : From KA Ericsson (academician behind the notion of “deliberate practice{ ) to Daniel Coyle (pop science book author)  -  all have emphasized this aspect. Again a visual to summarizes the key idea :


When you are first chunking a concept, its pre-chunked parts take up all your working memory, as shown on the left. As you begin to chunk the concept, you will feel it connecting more easily and smoothly in your mind, as shown in the center. Once the concept is chunked, as shown at the right, it takes up only one slot in working memory. It simultaneously becomes one smooth strand that is easy to follow and use to make new connections. The rest of your working memory is left clear. That dangling strand of chunked material has, in some sense, increased the amount of information available to your working memory, as if the slot in working memory is a hyperlink that has been connected to a big webpage.

5) Pomodoro to prevent procrastination : Knowledge scattered around various blogs and talks are put in one place. The idea is that that you do work in slots of (25min work + 5 min break).image

6) { (Recall + Test > Reread) , ( Interleave + Spaced repetition > massed practice )  }
– These ideas resonate through out the book “Make it Stick”. This book though summarized the ideas and supplements them with this visuals such as :


Solving problems in math and science is like playing a piece on the piano. The more you practice, the firmer, darker, and stronger your mental patterns become.


If you don’t make a point of repeating what you want to remember, your “metabolic vampires” can suck away the neural pattern related to that memory before it can strengthen and solidify.

7) Memory enhancement hacks :
Most of the ideas from “Moonwalking with Einstein” and other such memory hack books are summarized for easy reading

8) Reading / engaging in diverse material pays off : This has been a common trait amongst many people who do brilliant stuff. Pick up any person who has accomplished something significant, you will find they have varied interests.


Here you can see that the chunk— the rippling neural ribbon— on the left is very similar to the chunk on the right. This symbolizes the idea that once you grasp a chunk in one subject, it is much easier for you to grasp or create a similar chunk in another subject. The same underlying mathematics, for example, echo throughout physics, chemistry, and engineering— and can sometimes also be seen in economics, business, and models of human behavior. This is why it can be easier for a physics or engineering major to earn a master’s in business administration than someone with a background in English or history. Metaphors and physical analogies also form chunks that can allow ideas even from very different areas to influence one another. This is why people who love math, science , and technology often also find surprising help from their activities or knowledge of sports, music, language, art, or literature.

9) Adequate sleep is essential for better learning : This is like turning the lights off on the theatre stage so that artists can take a break, relax and come back for their next act. Not turning off the mind and overworking can only lead us to an illusion of learning, when in fact all we are doing is showcasing listless actors on the stage(working memory).


Toxins in your brain get washed away by having an adequate amount of sleep everyday.

The book can easily be read in an hour or two as it is filled with lot of images/ metaphors/ anecdotes and recurrent themes. The content of this book is also being offered in the form of  4 week course at Coursera

Lady Luck favors the one who tries

– Barbara Oakley


In today’s world, parents are extremely observant about how their children are learning. Be it academics or music or sport any other field that the child has developed a semblance of liking, the parent gives and seeks all the guidance available to make his/her kid’s learning process effective. Given the hyperconnected instant gratification world that we are all living it, Kids left to their own devices, become just that, in the literal sense. Their lives are surrounded by world of devices (cell phones, gaming consoles, ipod, ipad, etc.) and naturally they develop an affinity towards them. One doesn’t need some academic research to infer that attention spans are going down across all age groups, more so in children. In such an environment, can parents or teachers be confident that the children develops thinking and meta-thinking(thinking about how they are thinking )skills to become effective learners ?.

There is a mad rush towards alternative education schools everywhere. Parents are under the notion that schools that focus on standardized testing and standardized learning might not be effective for their kid whom they think is somehow “special” from everyone. In what sense they are “special”, only future would tell, but that doesn’t stop them from thinking that education must be somehow customized to suit their kid’s learning style.

In my own family, I have seen my cousin’s kids being put through a school where there are no tests at all until 8th or 9th grade. The school advertises to the general public saying that their USP is small class room sizes and NO TESTS. The admission process in the school creates a massive frenzy amongst everyone and even gets cited in the local newspapers. Parents feel that this “NO TEST” environment will unleash creativity amongst their kids and turn their little ones in to a creative genius. Is it really true that an environment without tests fosters good learning? Why is there a universal backlash against “tests”? Why is everyone fixated on “learning styles”? What is wrong with the current educational system? How does one become an effective learner? These and many more questions are answered in this book. Here is an attempt to summarize the book.

Learning Is Misunderstood

This chapter is a prelude to the book and lists down the claims that the authors verify via field research in various chapters of the book. What are the claims made at the outset?

  • Learning is deeper and more durable when it’s effortful. Learning that’s easy is like writing in sand, here today and gone tomorrow.
  • We are poor judges of when we are learning well and when we’re not. When the going is harder and slower and it doesn’t feel productive, we are drawn to strategies that feel more fruitful, unaware that the gains from these strategies are often temporary.
  • Rereading text and massed practice of a skill or new knowledge are by far the preferred study strategies of learners of all stripes, but they’re also among the least productive. By massed practice we mean the single-minded, rapid-fire repetition of something you’re trying to burn into memory, the “practice-practice-practice” of conventional wisdom. Cramming for exams is an example . Rereading and massed practice give rise to feelings of fluency that are taken to be signs of mastery, but for true mastery or durability these strategies are largely a waste of time.
  • Retrieval practice—recalling facts or concepts or events from memory— is a more effective learning strategy than review by rereading. Periodic practice arrests forgetting, strengthens retrieval routes, and is essential for hanging onto the knowledge you want to gain.
  • When you space out practice at a task and get a little rusty between sessions, or you interleave the practice of two or more subjects, retrieval is harder and feels less productive, but the effort produces longer lasting learning and enables more versatile application of it in later settings.
  • Trying to solve a problem before being taught the solution leads to better learning, even when errors are made in the attempt.
  • People do have multiple forms of intelligence to bring to bear on learning, and you learn better when you “go wide,” drawing on all of your aptitudes and resourcefulness, than when you limit instruction or experience to the style you find most amenable.
  • When you’re adept at extracting the underlying principles or “rules” that differentiate types of problems, you’re more successful at picking the right solutions in unfamiliar situations. This skill is better acquired through interleaved and varied practice than massed practice.
  • In virtually all areas of learning, you build better mastery when you use testing as a tool to identify and bring up your areas of weakness.
  • Elaboration is the process of giving new material meaning by expressing it in your own words and connecting it with what you already know. The more you can explain about the way your new learning relates to your prior knowledge, the stronger your grasp of the new learning will be, and the more connections you create that will help you remember it later.
  • Rereading has three strikes against it. It is time consuming. It doesn’t result in durable memory. And it often involves a kind of unwitting self-deception, as growing familiarity with the text comes to feel like mastery of the content.
  • It makes sense to reread a text once if there’s been a meaningful lapse of time since the first reading, but doing multiple readings in close succession is a time-consuming study strategy that yields negligible benefits at the expense of much more effective strategies that take less time. Yet surveys of college students confirm what professors have long known: highlighting, underlining, and sustained poring over notes and texts are the most-used study strategies, by far.
  • Rising familiarity with a text and fluency in reading it can create an illusion of mastery. As any professor will attest, students work hard to capture the precise wording of phrases they hear in class lectures, laboring under the misapprehension that the essence of the subject lies in the syntax in which it’s described. Mastering the lecture or the text is not the same as mastering the ideas behind them . However, repeated reading provides the illusion of mastery of the underlying ideas. Don’t let yourself be fooled. The fact that you can repeat the phrases in a text or your lecture notes is no indication that you understand the significance of the precepts they describe, their application, or how they relate to what you already know about the subject.

All the above claims are verified by experiments carried out in various school settings and other unconventional places. The authors at the very beginning make it clear that the learning theories that have been handed down to us have been a result of theory, lore and intuition. But over the last forty years and more, cognitive psychologists have been working to build a body of evidence to clarify what works and to discover the strategies that get results.

To Learn Retrieve

We all forget things. If they are trivial stuff, they really don’t matter. But if they are key principles, concepts, then our learning will be stunted and it becomes painfully obvious that we need to re-read the forgotten stuff. To give a specific example, let’s say I am learning about Jump modeling and there is an introductory section on Poisson processes. In the past I would have spent some time going over Poisson processes and understanding the math behind it. The key theorems are somewhere in my memory. Not all are at my beck and call. So, whenever I come across a concept that I have tough time recalling, my usual strategy is to re-read the old section. Not an ideal strategy, says this chapter. I think most of us follow the above strategy where re-reading is the goto choice to make things fresh. The chapter focuses on one key point – retrieval practice. This is a kind of practice where you make an effort to recall those concepts from your memory, reflect on those concepts from time to time. This is not the same as rereading the text.

The authors make a strong case for “testing” as a means of retrieval practice. The retrieval effect in the cognitive psychology field is known as “testing effect”. Through the results of various experiments conducted, the authors suggest that testing immediately after a lecture, or testing yourself at spaced intervals is far better than rereading at spaced intervals. Repeated retrieval ties the knot of memory. Retrieval must be spaced out rather than becoming a mindless repetition. It should require cognitive effort. The authors back up these suggestions with field experiments that show that frequent testing of students with delayed feedback gave better performance than merely rereading or revisiting the material before midterm and end term.

For an adult learner, how does this apply? I guess one must self test, even though it is painful. It is actually better if it is painful as it leads to greater effort at retrieval and hence better learning. How should the tests be designed? For programming there are many suggestions out there. For something like math, I think the best way is to read a theorem and try to give a proof in your own words trying to recall whatever you have learnt the previous time around. Merely reading through the proofs or concepts will not make the learning stick. This is called the “generation effect “. You generate the proof from some clues. In the case of frameworks or set of ideas, you can probably write an essay recalling all the aspects of the theory without rereading. It is easy to fall in to the trap of ,” Ok I have forgotten, let me reread the material”. Instead this chapter says that one must pause, take a self test, then quiz yourself as you go over the material again, and then reflect on what you have relearnt. This has a term called “elaboration” in the literature. This means you elaborate the learning or practice session so that memory paths are strengthened. The other thing I have started following recently is to take a small 60 page booklet and keep noting down whatever you find interesting for the day in the form of statements, visuals or just about anything that captures the learning. Obviously as you go along these 60 page diaries accumulate. Once in a while you can pick a booklet and read the statements that you found interesting a month ago, 6 months ago, a year ago. This is a kind of retrieval practice where you are trying to learn better by testing yourself.


Mix up practice

The authors introduce a term called “mass practice” where you keep practicing one aspect of skill development until you are good at it and then move on. This is clearly seen in textbooks where each chapter is followed by a set of problems that are only relevant to that chapter and the reader is asked to practice the exercises and then move on to the next chapter. This is the usual advice passed on to us from many people. Practice, practice until the skill is burned in to the memory. Faith in focused repetitive practice is everywhere and this is what the authors mean by “mass practice” Practice that is spaced out, interleaved with other learning, and varied produces better mastery, longer retention and more versatility. There is one price to pay though. From the part of the learner, it requires more effort. There are no quick positive affirmations that come with mass practice. Let’s say you have been immersed in doing Bayesian analysis for a few months, then you take a break and get back to it, there will be an inherent slowness at which you can digest things as those concepts are lying somewhere in your long term memory and invoking them takes effort. But the authors say that this is a good thing. Even though learning feels slower, this is the way to go.

This phenomenon of “mass practice” is everywhere. Summer camps, focused workshops, training seminars. Spacing out your practice feels less productive for the very reason that some forgetting has set in and you’ve got to work harder to recall concepts. It doesn’t feel like you’re on top of it. What you don’t sense in the moment is that the added effort is making the learning stronger.

Why does spaced practice work? Massed practice is good for short term memory. But the sad part is that such a practice does not lead to durable learning. For something to get in to long term memory, there should be consolidation in which memory traces are strengthened. If you do not activate these memory traces, then the paths will be lost. It is like laying a new road and using it for a week or so, and then moving on. Unless you use the road often, the material never gets a chance to become strong and in the process loses vitality.

Practice also has to interleaved. Interleaving is practicing two or more subjects or two different aspects of the same subject . You cannot study one aspect of subject completely and move on to another subject and so on. Linearity isn’t good. Let’s say you are learning some technique, for example EM algorithm. If you stick to data mining field, you will see its application in let’s say mixture estimation. However by interleaving your practice with let’s say state space models, you see that EM algorithm being used to estimate hyperparameters of a model. This interleaving of various topics gives a richer understanding. Obviously there is a price to pay. The learner is just about learning to understand something, when he is asked to move to another topic. So, that sense of feeling that he hasn’t got a full grasp on the topic remains. It is a good thing to have but an unpleasant situation that a learner must handle.

Varied practice – Let’s say you are a quant and trying to build financial models. Varied practice in your case would be to build a classification model, a Bayesian inference model, a Brownian motion based model, a more generic Levy process based model, a graph based model etc. The point is that you develop a broader understanding of relationships between various aspects of model building. If you stick to let’s say financial time series for an year, then move on to machine learning for another year, it is likely that you are going to miss connections between econometric models and machine learning models. Having said that, it is not a pleasant feeling to incorporate varied practice in one’s schedule. Imagine you are just about understand the way to build a particle filter, a technique to do online estimation of state vector and you have already spent quite an amount of time on that subject. It is time to move to another area, let’s say building a levy process based model. As soon as you start doing something on Levy process, you sense that your knowledge Poisson + Renewal processes is very rusty and the learning is extremely slow. This is the unpleasant part. But the authors have a reassuring message. When the learning appears slow and effortful, that is where real learning is taking place.

Compared to mass practice, a significant advantage of interleaving practice is that they help us learn to assess context and discriminate between problems, selecting and applying problems from a range of possibilities. The authors give an example of “learning painting styles” to drive home the point of interleaved and varied practice.

Practice like you play and you will play like you practice. The authors stress the importance of simulations for better practice. If you are in to trading strategy development, simulating time series and testing the strategy out of sample is fundamental for a better understanding of the strategy. In fact, with the rise of MCMC, the very process of estimation and model selection is done via simulation. The authors also bring out an example where daily reflection can be done as a form of retrieval practice.

I liked the last section of this chapter where the authors share the story of Georgia university football coach who is following the principles of retrieval, spacing, interleaving, variation, reflection and elaboration, in making his college team a better playing team.


Embrace Difficulties

Short term impediments that make for stronger learning have come to be called desirable difficulties, a term coined by Elizabeth and Robert Bjork. The chapter starts with an example of military school where the trainees are not allowed to carry note books or write stuff. They have to listen, watch, rehearse and execute. Testing is a potent reality check on the accuracy of your own judgment of what you know how to do. The process of strengthening the long term memory is called consolidation. Consolidation and transition of learning to long-term storage occurs over a period of time. An apt analogy for how the brain consolidates new learning is the experience of composing an essay. Let’s say you are studying point processes, a class of stochastic processes. First time around you might not be able to appreciate all the salient points of the text. You start out feeling disorganized and the most important aspects are not salient. Consolidation and retrieval helps solidify these learning’s. If you are practicing over and over again in some rapid-fire fashion, you are leaning on short term memory and very little mental effort is needed. There is an instant improvement, but the improvement is not robust enough to sustain. But if you practice by spacing and interleaving, the learning is much deeper and you will retrieve far easily in the future.

Durable robust learning means we do two things – First, as we recode and consolidate new material from short term memory into long term memory, we must anchor there securely. Second, we must associate it with a diverse set of cues that will make us adept at recalling the material later. Having effective retrieval clues is essential to learning and that is where tools like mindmaps help a lot. The reason we don’t remember stuff is that we don’t practice and apply it. If you are in to building say math/stat models, it is essential to at least simulate some data set, build a toy model so that practice gets some kind of anchorage for retrieval. Without this, any reading of a model will stay in your working memory for some time and then vanish. Knowledge, learning and skills that are vivid, hold significance, and those that are practiced periodically stay with us. Our retrieval capacity is limited and is determined by the context, by recent use, and the number and vividness of the cues that you have linked to the knowledge and can call on to help it bring it forth.

Psychologists have uncovered a curious inverse relationship between ease of retrieval practice and the power of that practice to entrench learning, the easier knowledge or skill is for you to retrieve, the less your retrieval practice will benefit your retention of it.

There is an excellent case study of a baseball team where the team is split in to two and they are given varied practice regimen. First group practices 45 pitches evenly divided in to sets of three where each set has a specific type of pitch thrown. The second group also practices 45 pitches but this time, the pitches were randomly interspersed. After the training, the first group feels good about their practice while the second group feels that they were not developing their skills properly. However when it came to the final performance test, the second group performed far better than the first group. This story illustrates two points – first, our judgments of what learning strategies work best for us are often mistaken, colored by illusions of mastery. Second, some difficulties that require more effort and slow down apparent gains will feel less productive but will more than compensate for that by making the learning stronger, precise and durable. The more you have forgotten a topic, the more effective relearning will be in shaping your permanent knowledge. The authors also make it a point to highlight that if you struggle to solve a problem before being shown how to solve it, the subsequent lesson is better learned and more durably remembered.

This chapter and this book is an amazing fountainhead of ideas that one can use. Not everything is new but the fact that there is an empirical evidence to back it up means that you know that it is not folklore wisdom. One thing I learnt from the book which has reinforced my way of learning is “write to learn”. After reading a book or reading a concept, I try to write it down so that I can relate to things that I have already learnt, relate to aspects of the field that I want to eventually apply etc. This obviously takes up a lot of time, but the learning is far more robust. I think book summaries that I manage to write is one of the best ways to reflect on the main contents of the book. I tend to write a pretty detailed summary of key ideas so that the summary serves as a material for retrieval practice at a later point in time.

The other idea this chapter talks about is about the need to commit errors to solidify learning. Came to know about “Festival of errors” and “Fail conference”. There is also a story about Bonnie, a writer and self-taught ornamental gardener, who follows the philosophy, “ leap before you look because if you look, you probably won’t like what you see”. Her garden writing appears under the name “Blundering Gardener”. Bonnie is a successful writer and her story goes on to show that struggling with a problem makes for stronger learning and how a sustained commitment to advancing in a particular field of endeavor by trial-and-error leads to complex mastery and greater knowledge of interrelationships of things. Bonnie’s story is pretty inspiring for anyone who wishes to tackle a difficult field. By going head long in to the field and learning from the trial and error process, and then writing about the entertaining snafus and unexpected insights, she is doing two things. Firstly, she is retrieving the details and elaborating the details. “Generative learning” means learner is generating the answer than recalling it. Basically it means learn via trial-and-error.


  • Learning is a three step process – Initial encoding, consolidation and retrieval
  • Ability to recall what you already have depends on the repeated use of information and powerful retrieval clues
  • Retrieval practice that’s easy does little to strengthen learning, the more difficult the practice, the greater the benefit
  • Retrieval needs to be spaced. When you recall something from your memory when it has already become rusty, you need more effort and this effortful retrieval strengthens memory and makes learning pliable
  • Practice needs to be interleaved and varied
  • Trying to come up with an answer rather than presenting it to you leads to better learning and retention

Avoid Illusions of knowing

The chapter starts by describing two modes of thinking System 1 and System 2, from Daniel Kahneman’s book and says that we base our actions based on System 1 more often than System 2. Our inclination to finding narratives means that it has a significant say in our memory capabilities. There are lot of illusions and misjudgments that we carry along. One way to escape from them is to replace subjective experience as the basis for decisions with a set of objective gauges outside ourselves, so that our judgments squares with the real world around us. When we have reliable reference points, we can make good decisions about where to focus our efforts, recognize where we’ve lost our bearings, and find out way again. It is important to pay attention to the cues you are using to judge what you have learned. Whether something feels familiar or fluent is not always a reliable indicator of learning. Neither is your level of ease in retrieving a fact or phrase on a quiz shortly after the text. Far better is to create a mental model of the material that integrates various ideas of the text, connects to what you already know, and enables you to draw inferences. How ably you can explain the text is an excellent cue for judging comprehension, because you must recall the salient points, put in your own words and give the logic of how it connects to everything else.

Get beyond your learning styles

It is a common statement that you come across in the media, “every kid is different, the learning style has to be specific and catering to the kid’s learning style”. On the face of it, the statement looks obvious. Empirical evidence however does not support it. The authors give a laundry list of all the learning styles that have been put forth and say that there is absolutely no evidence that catering to individual learning style makes any difference. The simple fact that different theories embrace such wildly discrepant dimensions gives cause for concern about their scientific underpinnings. While it’s true that most all of us have a decided preference for how we like to learn new material, the premise behind learning styles is that we learn better when the mode of presentation matches the particular style in which an individual is best able to learn. That is the critical claim.

The authors say that

Moreover, their review showed that it is more important that the mode of instruction match the nature of the subject being taught: visual instruction for geometry and geography, verbal instruction for poetry, and so on. When instructional style matches the nature of the content, all learners learn better, regardless of their differing preferences for how the material is taught.

So, if the learning styles don’t matter, how should one go about ? The authors mention two aspects here

  1. Structure building: There do appear to be cognitive differences in how we learn, though not the ones recommended by advocates of learning styles. One of these differences is the idea mentioned earlier that psychologists call structure building: the act, as we encounter new material, of extracting the salient ideas and constructing a coherent mental framework out of them. These frameworks are sometimes called mental models or mental maps. High structure- builders learn new material better than low structure-builders.
  2. Successful intelligence: Go wide: don’t roost in a pigeonhole of your preferred learning style but take command of your resources and tap all of your “intelligences” to master the knowledge or skill you want to possess. Describe what you want to know, do, or accomplish. Then list the competencies required, what you need to learn, and where you can find the knowledge or skill. Then go get it. Consider your expertise to be in a state of continuing development, practice dynamic testing as a learning strategy to discover your weaknesses, and focus on improving yourself in those areas. It’s smart to build on your strengths, but you will become ever more competent and versatile if you also use testing and trial and error to continue to improve in the areas where your knowledge or performance are not pulling their weight.


Increase your abilities

This chapter starts off by giving some famous examples like the popular Marshmallow study, Memory athletes to drive home the point that brain is every changing. This obviously means that the authors take the side of nurture in the nature vs. nurture debate. The brain is remarkably plastic, to use the term applied in neuroscience, even into old age for most people. The brain is not a muscle, so strengthening one skill does not automatically strengthen others. Learning and memory strategies such as retrieval practice and the building of mental models are effective for enhancing intellectual abilities in the material or skills practiced, but the benefits don’t extend to mastery of other material or skills. Studies of the brains of experts show enhanced myelination of the axons related to the area of expertise but not elsewhere in the brain. Observed myelination changes in piano virtuosos are specific to piano virtuosity. But the ability to make practice a habit is generalizable. To the extent that “brain training” improves one’s efficacy and self-confidence, as the purveyors claim , the benefits are more likely the fruits of better habits, such as learning how to focus attention and persist at practice.

After an elaborate discussion on IQ, the authors suggest three strategies to amp up the performance levels :

  1. Maintaining a growth mindset — Carol Dweck’s work is used as the supporting argument. Dweck came to see that some students aim at performance goals, while others strive toward learning goals. In the first case, you’re working to validate your ability. In the second, you’re working to acquire new knowledge or skills. People with performance goals unconsciously limit their potential. If your focus is on validating or showing off your ability, you pick challenges you are confident you can meet. You want to look smart, so you do the same stunt over and over again. But if your goal is to increase your ability, you pick ever-increasing challenges , and you interpret setbacks as useful information that helps you to sharpen your focus, get more creative, and work harder.
  2. Deliberate Practice – Well, this has become a common term after many authors have written journalistic accounts of Anders Ericsson’s research. In essence it means that expert performance in medicine, science, music, chess, or sports has been shown to be the product not just of innate gifts, as had long been thought, but of skills laid down layer by layer, through thousands of hours of dedicated practice.
  3. Memory cues – Until a learner develops a deep learning of a subject, he/she can resort to mnemonic devices. Conscious mnemonic devices can help to organize and cue the learning for ready retrieval until sustained, deliberate practice and repeated use form the deeper encoding and subconscious mastery that characterizes expert performance.

It comes down to the simple but no less profound truth that effortful learning changes the brain, building new connections and capability. This single fact— that our intellectual abilities are not fixed from birth but are, to a considerable degree, ours to shape— is a resounding answer to the nagging voice that too often asks us “Why bother?” We make the effort because the effort itself extends the boundaries of our abilities. What we do shapes who we become and what we’re capable of doing. The more we do, the more we can do. To embrace this principle and reap its benefits is to be sustained through life by a growth mindset. And it comes down to the simple fact that the path to complex mastery or expert performance does not necessarily start from exceptional genes, but it most certainly entails self-discipline, grit, and persistence ; with these qualities in healthy measure, if you want to become an expert, you probably can. And whatever you are striving to master, whether it’s a poem you wrote for a friend’s birthday, the concept of classical conditioning in psychology, or the second violin part in Hayden’s Fifth Symphony, conscious mnemonic devices can help to organize and cue the learning for ready retrieval until sustained, deliberate practice and repeated use form the deeper encoding and subconscious mastery that characterize expert performance.


Make It Stick

The authors implement the lessons from the book within the confines of the book itself. This chapter is like a spaced repetition of all the ideas mentioned in the previous chapters. So, if you don’t bother about the empirical evidence, you can just read this chapter and take them at face value, incorporate them in your schedule and see if they make sense.


This is by far best book I have read that talks about “ how to go about learning something? ”. There are gems in this book that any learner can incorporate in one’s schedule and see a drastic change in their learning effectiveness. The book is a goldmine for students, teachers and life-long learners. I wish this book was published when I was a student!.


The authors are math professors at Princeton. This book is a result of a 7 year effort. It distills all their math teaching experiences in to 150 pages. The book is targeted towards general audience even though most of anecdotes are from a classroom environment.

The authors use the 5 classic Greek elements that were thought to be the foundation of everything – Earth, Fire, Air, Water and Quintessential – to lay out the principles of effective thinking. The authors had approached Princeton university press with a novel idea, i.e., make three copies of the same book and bundle it to one fat book and sell it. The thought process being the book needs to be read at least three times. In the first read, you should read cover to cover to get the big picture of the book. In the second read you are supposed to pause at various points of the book and go over the action items carefully and in the third read, you are to read randomly across various sections and see the connections. The Princeton press with all due respect to the authors rejected their novel idea. So, the book is just about 150 pages but definitely deserves to be read a couple of times to get the best out of it.

The authors give the following connection between 5 classic Greek elements and 5 elements of thinking

clip_image002 Strive for rock-solid understanding
clip_image004 Fail and learn from those missteps
clip_image006 Constantly create and ask challenging questions
clip_image008 Consciously consider the flow of ideas
clip_image010 Learning is a lifelong journey; thus each of us remains a work-in-progress— always evolving, ever changing— and that’s Quintessential living.

Well, none of this is something that we have not come across before. We already know all this at some level but this book brings those memories in to the present. Having these principles in working memory, will make us constantly question the way we go about learning, the way we work and the way we apply thinking in our lives.