The One World Schoolhouse: Education Reimagined

by Salman Khan

  Well, with reviews like that, you might have thought that mastery learning would be a long-running show. But it wasn’t. As in the 1920s, the method enjoyed a brief vogue, then was swamped by the stagnant waters of traditional classroom procedures. As before, the reason was partly economic; it still cost money to print and distribute all those workbooks, test forms, and individualized reading materials. But money wasn’t the only hurdle. Once again there was the resistance of administrators and bureaucrats. Change was difficult; change was frightening. The old way worked well enough… didn’t it? Lacking some clear and present urgency to leave the comfort zone of lectures and traditional textbooks, why bother? And so in spite of the fact that mastery learning had consistently demonstrated both anecdotal and statistical benefits for both students and teachers, it went out of fashion once again.

  Cut to the present moment. Human nature hasn’t changed. Bureaucrats and organizations still seem to have a built-in aversion to new ideas and approaches. People in all fields still have a tendency to protect their turf, sometimes at the expense of the greater good. In other regards, however, things are quite different this time around. More than ever before, there is a sense of urgency when it comes to educational reform. The old system is failing us; it needs to be rethought. On this there is broad agreement.

  The other thing that has changed—and this is huge—is that technology has radically lowered the expenses formerly associated with mastery learning. No more paper workbooks. No more pricey printings of individualized exercises. Everything needed for self-paced learning is right there in the computer; the cost of delivering it to students is miniscule. The old excuse that newfangled teaching methods are just too expensive—or are only the province of elite schools in privileged communities—just no longer applies.

  There’s one more aspect of mastery learning systems that I’d like to explore before moving on: the relationship between mastery learning and personal responsibility.

  Taking responsibility for education—responsibility on the part of students, families, communities, and nations—is of course a hot-button issue these days, approached and argued from all points on the political compass. Too often, however, the suggestion is made that “taking responsibility” is somehow an independent thing from the learning itself, and that responsibility can be put on the shoulders of parents and teachers without necessarily involving the student. Both of those notions are false. Taking responsibility for education is education; taking responsibility for learning is learning. From the student’s perspective, only by taking responsibility does true learning become possible; studies of mastery learning dynamics make this clear.

  In one such study, it was observed that students in mastery programs “developed more positive attitudes about learning and about their ability to learn.”7 To use a contemporary expression, they were more likely to claim ownership of their educations. Another study concluded simply that “students who learned under mastery conditions… accepted greater responsibility for their learning.”8

  I stress this because I believe that personal responsibility is not only undervalued but actually discouraged by the standard classroom model, with its enforced passivity and rigid boundaries of curriculum and time. Denied the opportunity to make even the most basic decisions about how and what they will learn, students stop short of full commitment.

  Mastery learning, then, is another one of those ideas for which I take no credit whatsoever. Both the concept itself and the data in support of its effectiveness have been around for quite a while. But as we’ll see in due course, the Khan Academy presents an opportunity to apply its principles and reap its benefits far more broadly than ever before.

  How Education Happens

  Learning without thought is labor lost; thought without learning is perilous.

  —CONFUCIUS

  Let’s consider an incredibly fundamental riddle: How does education happen?

  I see it as an extremely active, even athletic process. Teachers can convey information. They can assist and they can inspire—and these are important and beautiful things. At the end of the day, however, the fact is that we educate ourselves. We learn, first of all, by deciding to learn, by committing to learning. This commitment allows, in turn, for concentration. Concentration pertains not only to the immediate task at hand but to all the many associations that surround it. All of these processes are active and deeply personal; all involve the acceptance of responsibility. Education doesn’t happen out in the ether, and it doesn’t happen in the empty space between the teacher’s lips and the students’ ears; it happens in the individual brains of each of us.

  This is no mere metaphor, but a physical reality. The Nobel Prize–winning neuroscientist Eric R. Kandel, in his seminal book In Search of Memory, argues that learning is in fact neither more nor less than a series of changes that take place in the individual nerve cells of which our brains are composed. When a given cell is involved in learning, it literally grows. The process is not exactly analogous to what happens when one exercises a muscle, but it’s pretty close. Without getting too terribly technical, what happens is that an “educated” neuron actually develops new synaptic terminals—these being the tiny appendages across which one neuron communicates with the next. The increase in the number of active terminals makes the nerve cell more efficient in passing messages along. As this process is repeated along an entire neural pathway leading to a particular region of the brain, the information is gathered and stored. As we work with the same concept from slightly different angles and investigate questions surrounding it, we build even more and deeper connections. Collectively, this web of connections and associations comprises what we think of informally as understanding.

  In physiological terms, then, learning means that our brains have done some exercise—digested information, connected concepts and memories in new ways—and our nerve cells have thereby been altered.

  How durable will this new understanding be? That depends, in part, on how actively the learning was acquired in the first place. Again, learning involves physical changes in the brain. Proteins are synthesized; synapses are enhanced. There’s a lot of chemical and electrical work going on, and this is why thinking actually burns a lot of calories. The more neurons recruited into the learning process, the more vivid and lasting the memory. These physical changes in the brain, however, are not permanent. What we think of as “forgetting” is actually the gradual loss or weakening of the extra connections acquired in the process of learning. But there’s good news here as well. As Kandel and other researchers have noticed, we don’t lose all the extra synapses we’ve acquired. Again, an analogy with physical exercise, while inexact, is helpful; stop working out for a while and you will lose some but not all of the strength you had acquired. Some of the benefit will remain.

  This is why it’s easier to learn something a second time; at least some of the necessary neural pathways are already there. It’s also a good incentive to bear down and concentrate the first time around, to etch the connections as durably as possible.

  The findings of Kandel and other neuroscientists have much to say about how we actually learn; unfortunately, the standard classroom model tends to ignore or even to fly in the face of these fundamental biological truths. Stressing passivity over activity is one such misstep. Another, equally important, is the failure of standard education to maximize the brain’s capacity for associative learning—the achieving of deeper comprehension and more durable memory by relating something newly learned to something already known. Let’s take a moment to consider this.

  Our brains hold two distinctly different kinds of memory—short-term and long-term. Short-term memory is not only fleeting, it’s very fragile as well, easily disrupted by a lapse in concentration or by even a momentary detour into a different task or subject. (As an everyday example of this, I often forget if I have already used shampoo when I am in the shower.)

  Long-term memory is far more stable and lasting, though of course not p
erfectly so. The process by which short-term memory becomes long-term memory is called consolidation. Brain scientists have yet to discover exactly how consolidation happens at the cellular level, but certain practical, functional characteristics of the process are well understood. As Kandel writes, “For a memory to persist, the incoming information must be thoroughly and deeply processed. This is accomplished by attending to the information and associating it meaningfully and systematically with knowledge already well established in memory” (italics mine).

  In other words, it’s easier to understand and remember something if we can relate it to something else we already know. This is why it’s easier to memorize a poem than a series of nonsense syllables of equal length. In a poem, each word relates to images in our minds and to what has come before; there are rules of rhythm and connection that we understand, even if subliminally, the poem must follow. Rather than memorizing individual bits of information, we are dealing with patterns and strands of logic that allow us to come closer to seeing something whole.

  This seems to be how our brains work best at retaining knowledge for the longer term, and it would certainly seem to suggest that the most effective way to teach would be to emphasize the flow of a subject, the chain of associations that relates one concept to the next and across subjects. Unfortunately, however, the standard approach to classroom teaching does just the opposite.

  This is most obviously seen in the artificial separation of traditional academic subjects. We lop them off at ultimately arbitrary places; we ghettoize them. Genetics is taught in biology while probability is taught in math, even though one is really an application of the other. Physics is a separate class from algebra and calculus despite its being a direct application of them. Chemistry is partitioned off from physics even though they study many of the same phenomena at different levels.

  All of these divisions limit understanding and suggest a false picture of how the universe actually works. Wouldn’t students find it useful to understand how contact forces (studied in physics) are in fact an expression of the repulsive forces between electrons (studied in chemistry)? Wouldn’t algebra seem a tad more interesting if it could also be used to figure out how fast you hit the water on a belly flop or how heavy you would be on a planet twice Earth’s mass? For that matter, think about the interesting cross-pollination that might occur if a value-neutral subject like computer science were studied together with a value-laden subject like evolution; what might students learn by writing computer programs to simulate variation and competition in an ecosystem?

  The possibilities are endless, but they can’t be realized given the balkanizing habits of our current system. Even within the already sawed-off classes, content is chunked into stand-alone episodes, and the connections are severed. In algebra, for example, students are taught to memorize the formula for the vertex of a parabola. Then they separately memorize the quadratic formula. In yet another lesson, they probably learn to “complete the square.” The reality, however, is that all those formulas are expressions of essentially the same mathematical logic, so why aren’t they taught together as the multiple facets of the same concept?

  I’m not just nitpicking here. I believe that the breaking up of concepts like these has profound and even crucial consequences for how deeply students learn and how well they remember. It is the connections among concepts—or the lack of connections—that separate the students who memorize a formula for an exam only to forget it the next month and the students who internalize the concepts and are able to apply them when they need them a decade later.

  This piecemeal approach to teaching is hardly limited to math and science. Similar instances can easily be found in the humanities. For an example from the subject of history, consider the Napoleonic Wars and the Louisiana Purchase. These were closely related events; Louisiana was offered at a fire-sale price only because Napoleon was desperate to finance his land wars in Europe and had had his navy destroyed at Trafalgar (so he couldn’t protect Louisiana even if he wanted to keep it). But what are kids taught? If they’re American, they tend to be taught that Thomas Jefferson got a great deal, with very little context as to why the Americans had a lot more negotiating leverage than Napoleon. These partial facts do nothing to promote an accurate understanding of how interconnected the world was and continues to be.

  In our misplaced zeal for tidy categories and teaching modules that fit neatly into a given length of class time, we deny students the benefit—the physiological benefit—of recognizing connections. The conventional educational approach tends to be drearily consistent; take a piece of a subject and treat it as if it existed in a vacuum. Spend one or three or six weeks of classroom lectures on it, then give a test and move on. No wonder so many students acknowledge that they largely forget a subject soon after they’ve been tested on it.

  Well, why shouldn’t they forget? First of all, it’s likely that they’ve been denied the mnemonic advantage of having this most recent module related to subjects that have come before or to their existing life experience. Second, chances are that the students have not been given a sufficient appreciation of how mastery of this topic will lead to a deeper understanding of things that come after. In short, if a given subject has been sealed, wrapped, and tied up with a bow—if the message is that the subject is finished—why bother to remember it?

  In gradually developing my own approach to teaching, one of my central objectives was to reverse this balkanizing tendency. In my view, no subject is ever finished. No concept is sealed off from other concepts. Knowledge is continuous; ideas flow.

  An example of this is something we at the Khan Academy call the knowledge map. By 2006, when I was tutoring my cousins and a handful of family friends, I had made about sixty question generators for various concepts, and I was beginning to have a hard time keeping track of my tutees’ individual progress through the series. I had already been drawing graphlike structures on paper to illustrate which concepts were prerequisites for others, so I decided to write some software that would thread these together and automatically assign new exercises. It looked kind of cool once I had done my first pass, and I thought that my cousins might enjoy seeing the “map” of all the concepts in the system. It was a big hit with them and became a core piece of the Khan Academy software platform. In stressing the connections among subjects and giving learners a visual picture of where they’ve been and where they’re going, we hope to encourage students to follow their own paths—to move actively up, down, and sideways, wherever their imaginations lead.

  This—admittedly by a rather circuitous path—brings us back to the issue of personal responsibility.

  Given that learning involves physical changes in each of our individual brains, and given that knowledge consists not of some linear progression but rather the gradually deepening comprehension of a vast web of concepts and ideas, a surprising corollary presents itself: No two educations are the same.

  There is a very refreshing irony here. You can standardize curricula, but you can’t standardize learning. No two brains are the same; no two pathways through the infinitely subtle web of knowledge are the same. Even the most rigorous standardized tests demonstrate only an approximate grasp of a certain subset of ideas that each student understands in his or her own way. Personal responsibility for learning goes hand in hand with a recognition of the uniqueness of each learner.

  Filling in the Gaps

  Do you wish to be great? Then begin by being. Do you desire to construct a vast and lofty fabric? Think first about the foundations of humility. The higher your structure is to be, the deeper must be its foundation.

  —SAINT AUGUSTINE

  There is no such thing as a “perfect” learner.

  There is no such thing as a student who “gets” every subject the first time through. In fact, most of the very brightest people I know enjoy revisiting basic ideas and seeing even deeper layers, fully realizing that they might never fully “get” most things. Even if there were someone with
the potential to “get” everything, she would have to have had the extraordinary good luck to have nothing but excellent resources and teachers, to have gotten through her school years without being home with the flu, and to be improbably level in her focus and her moods. In the real world, this just doesn’t happen. Every student, no matter how bright or how motivated, struggles now and then. Every student—even my cousin Nadia—is occasionally confused. Every student forgets things or, by a combination of faulty teaching methods and human limitations, fails to grasp some crucial concepts and connections.

  This less-than-tidy reality raises a number of questions. Can the inevitable gaps and lapses be repaired; and if so, how? Who bears the responsibility for recognizing the misconceptions and the stumbling places, and for putting in the time and effort to fix them?

  I firmly believe that gaps in learning can be repaired, and moreover that they must be repaired if future, more advanced concepts are to be mastered. Subjects evolve one from another; one subject’s climax is the starting point for the next. A gap or misconception in a previous subject therefore becomes a stumbling block in the one that follows.

  But there’s good news in this as well. We’ve noted that our brains seem to work most efficiently when aided by associations, by links. When a link is missing—say, for example, if we don’t quite understand how simple division evolves into long division—we ourselves can often identify the source of the difficulty.