Excerpts for One World Schoolhouse : Education Reimagined

The One World Schoolhouse

Education Reimagined
By Salman Khan


Copyright © 2012 Salman Khan
All right reserved.

ISBN: 9781455508389


Learning to Teach

Teaching Nadia

There is an art, or rather, a knack to flying. The knack lies in learning how to throw yourself at the ground and miss. Pick a nice day and try it.


This story starts with one student and one teacher. It begins as a family story, so let me tell you a bit about my background.

I was born in Metairie, Louisiana, a residential area within metro New Orleans. My father, a pediatrician, had moved there from Bangladesh for his medical residency at LSU and, later, his practice at Charity Hospital. In 1972, he briefly returned to Bangladesh and came back with my mother—who was born in India. It was an arranged marriage, very traditional (my mother tried to peek during the ceremony to make sure she was marrying the brother she thought she was). Over the next several years, five of my mother’s brothers and one cousin came to visit, and they all fell in love with the New Orleans area. I believe that they did this because Louisiana was as close to South Asia as the United States could get; it had spicy food, humidity, giant cockroaches, and a corrupt government. We were a close family—even though, at any given moment, half of my relatives weren’t speaking to the other half.

Still, a family wedding was a big occasion, so when I got married in 2004, more than forty relatives made the long trip to New Jersey, where my wife’s family lived. One of them was my cousin Nadia.

Today, Nadia is a pre-med junior at Sarah Lawrence College. But in 2004 she was a very serious-minded twelve-year-old who had just had the first academic setback of her life. She’d done poorly on a math placement exam given at the end of sixth grade. She was a straight-A student, highly motivated, always prepared. Her subpar performance baffled her. It wounded her pride, her confidence, and her self-esteem.

By the time we spoke after my wedding, Nadia had actually come to accept the outcome of that test. She believed that she just wasn’t good at math. I saw it very differently. I saw real potential in her. She was logical, creative, and tenacious. I was already viewing her as a future computer scientist or mathematician. It seemed inconceivable to me that she, of all people, would find something in the sixth grade difficult.

Having gone through the traditional academic system, it was also clear to me that being placed in the slower math class could be the kiss of death for her mathematical future. Because of “tracking”—a subject we’ll have occasion to come back to—this one test result would have huge ramifications for Nadia’s academic destiny. If she didn’t get into the more advanced track, she wouldn’t be able to take algebra in eighth grade. If she didn’t take algebra in eighth grade, she wouldn’t be able to take calculus in twelfth. And so on, down a slippery slope that would leave her far short of her potential.

But a botched test was a botched test. Was there anything to be done about it? Nadia’s mother didn’t think so, and during a post-wedding visit to Boston, where I lived and worked, it became clear that she was very distressed. So I made a somewhat rash offer. If Nadia’s school would let her retake the exam, I would tutor her, remotely, when she was back in New Orleans. As to exactly how I would tutor her… well, that was a work in progress.

Let me be clear—I think it’s essential for everything that follows—that at the start this was all an experiment, an improvisation. I’d had no teacher training, no Big Idea for the most effective way to teach. I did feel that I understood math intuitively and holistically, but this was no guarantee that I’d be effective as a teacher. I’d had plenty of professors who knew their subject cold but simply weren’t very good at sharing what they knew. I believed, and still believe, that teaching is a separate skill—in fact, an art that is creative, intuitive, and highly personal.

But it isn’t only an art. It has, or should have, some of the rigor of science as well. I felt that I could experiment with different techniques to see what worked and what didn’t, that with time I could develop myself into an effective tutor for Nadia. It was an intellectual challenge not too different from those I faced in the investing or technology worlds, but this one had the very real potential to empower someone I cared about.

I had no preconceived notions about how people learned; I was constrained by no orthodoxy regarding the “right” way to do things. I was feeling my way for how best to convey information and to employ the available technology. In short, I was starting from square one, without habits or assumptions. It’s not just that I was thinking outside the box; for me, there was no box. I tried things and I saw what worked. By extension, I also inferred what hadn’t been working.

Actually, I did bring a few assumptions into my approach to working with Nadia, though they were based on personal experience rather than on any sort of pedagogic theory. During my own school years I’d felt that some teachers were more interested in showing off what they knew than in communicating it to me. Their tone was often impatient, occasionally arrogant and even condescending. Other teachers were scripted to the point that it didn’t feel like they were actually even thinking. I wanted our tutorial sessions to be a safe, personal, comfortable, thought-provoking experience. I wanted to be a tutor who genuinely shared his thinking and expressed it in a conversational style, as if I was speaking to an equal who was fundamentally smart but just didn’t fully understand the material at hand.

I firmly believed that Nadia, and most people, could understand the math. I didn’t want her to memorize and I certainly didn’t want her to compartmentalize. I was convinced that if she understood the conceptual underpinnings of mathematics, the flow of one idea to the next, everything else would be easy.

In any case, the first step in tutoring Nadia was to figure out what aspect of the math test had given her trouble. It turned out that she had stumbled on the concept of unit conversion. This surprised me. Unit conversion—figuring out how many feet in six miles, or how many ounces in three pints, and so forth—was a fairly straightforward notion. You learned a few terms—kilo for a thousand, centi for a hundredth—and the rest of the factors you could easily look up. From there it was a simple matter of multiplication or division. Nadia had done just fine with far subtler concepts in math.

So why did she have trouble with unit conversion? She didn’t know, and neither did I. But let’s think about a few of the possible reasons that she might not have “gotten” this particular topic.

Maybe she was absent on the day it was introduced in class. Maybe she was physically present but not at her best. Maybe she was sleepy, or had a bellyache, or was upset about an argument with her mom. Maybe she had an exam in the class that came next, and was cramming for that instead of paying attention. Maybe she had a crush on a boy two rows over and was daydreaming about him. Maybe her teacher was in a hurry to move on and just didn’t explain it very well.

These are only conjectures; the point is that there are any number of things that might have prevented Nadia from catching on to unit conversion, and that once the concept had passed her by, it wasn’t coming back in class. That module had been covered. Those problems had been worked on and erased. There was a curriculum to follow, a schedule to keep; the class had to move on.

Let’s take a moment to consider this. It so happened that Nadia attended a fine prep school, with an excellent student/teacher ratio and quite small class sizes. Class size, of course, is an obsession among those who believe that our standard educational model would work just fine if only we could afford more teachers, more buildings, more textbooks, more computers—more of everything except students, so that class sizes could be reduced (essentially making poor schools look more like rich ones). Now, no one is against the idea of smaller classes; I want as low of a ratio as economically possible for my own children so they have time to really form bonds with their teachers. Unfortunately, however, the idea that smaller classes alone will magically solve the problem of students being left behind is a fallacy.

It ignores several basic facts about how people actually learn. People learn at different rates. Some people seem to catch on to things in quick bursts of intuition; others grunt and grind their way toward comprehension. Quicker isn’t necessarily smarter and slower definitely isn’t dumber. Further, catching on quickly isn’t the same as understanding thoroughly. So the pace of learning is a question of style, not relative intelligence. The tortoise may very well end up with more knowledge—more useful, lasting knowledge—than the hare.

Moreover, a student who is slow at learning arithmetic may be off the charts when it comes to the abstract creativity needed in higher mathematics. The point is that whether there are ten or twenty or fifty kids in a class, there will be disparities in their grasp of a topic at any given time. Even a one-to-one ratio is not ideal if the teacher feels forced to march the student along at a state-mandated pace, regardless of how well the concepts are understood. When that rather arbitrary “snapshot” moment comes along—when it’s time to wrap up the module, give the exam, and move on—there will still likely be some students who haven’t quite figured things out.

They could probably figure things out eventually—but that’s exactly the problem. The standard classroom model doesn’t really allow for eventual understanding. The class—of whatever size—has moved on.

In muddling toward my own approach to tutoring, then—in trying to match my methods to how I thought people really learn—two of my first precepts were these: that lessons should be paced to the individual student’s needs, not to some arbitrary calendar; and that basic concepts needed to be deeply understood if students were to succeed at mastering more advanced ones.

But let’s come back to Nadia.

She returned to school in New Orleans. I resumed my working life in Boston. I’d equipped us both with inexpensive pen tablets that would allow us to see each other’s scrawls on our respective computers, using a program called Yahoo Doodle. We scheduled sessions to talk on the phone and figure out this troublesome business of unit conversion.

The first week of tutoring was pure torture—torture for me, and I’m guessing it was ten times worse for her. But it taught me, in a very immediate and intimate manner, about some of the many complicating factors that get in the way of learning.

There was no doubt that Nadia was extremely bright. When she and her family had visited me in Boston, we’d killed some time by working on a battery of brain teasers while waiting for the Fourth of July fireworks to start over the Charles River. What I most remembered was how willing Nadia was to tackle hard problems. How analytical and creative she was. How she was able to logically break down questions that I’ve seen interviewees from top engineering and business schools struggle with. Yet when it came to unit conversion, her brain just seemed to shut down. It froze; it locked. Why? It seemed to me that she’d just plain psyched herself out. Like many people who’d had difficulty with a particular subject, she’d told herself she’d never get it, and that was that.

I told her, “Nadia, you’ve mastered much harder things than this. You’ll get this, too.”

Either she didn’t hear me or she thought I was lying to her. We started doing problems. I’d ask a question. There’d be a silence—a silence that went on so long I sometimes thought we’d lost the telephone or Internet connection. Finally her answer would come, meekly, with her voice turning up at the end. “A thousand?”

“Nadia, are you guessing?”

“A hundred?”

I was starting to get seriously concerned that perhaps I was doing Nadia more harm than good. With nothing but kind intentions, I was causing her a lot of discomfort and anxiety. My hope had been to restore her confidence; maybe I was damaging it still further.

This forced me to acknowledge that sometimes the presence of a teacher—either in the room or at the other end of a telephone connection; either in a class of thirty or tutoring one-to-one—can be a source of student thought-paralysis. From the teacher’s perspective, what’s going on is a helping relationship; but from the student’s point of view, it’s difficult if not impossible to avoid an element of confrontation. A question is asked; an answer is expected immediately; that brings pressure. The student doesn’t want to disappoint the teacher. She fears she will be judged. And all these factors interfere with the student’s ability to fully concentrate on the matter at hand. Even more, students are embarrassed to communicate what they do and do not understand.

With that in mind—and partly out of sheer exasperation—I tried a somewhat different strategy. I said, “Nadia, I know you’re smart. I’m not judging you. But we’re changing the rules here. You’re not allowed to guess, and you’re not allowed to give me wishy-washy answers. There are only two things I want to hear. Either give me a definite, confident answer—yell it out!—or say, ‘Sal, I don’t understand. Please go over it again.’ You don’t have to get it the first time. I won’t think less of you for asking questions or wanting something repeated. Okay?” I think it might have pissed her off a bit, but it had the right effect. She began decisively, and somewhat angrily, to shout answers—or admissions of lack of understanding—back at me.

Very soon after that, Nadia seemed to have one of those Aha moments. Unit conversion rather suddenly started making sense and the tutoring sessions became a lot of fun. Which came first, the success or the enjoyment? I don’t really know, and I don’t think it matters. What does matter is that along with her growing comfort with the subject, Nadia’s confidence and alertness came roaring back. I could hear her pleasure when she knew an answer. More important, there was no embarrassment or shame when she needed something explained again—when she hit the replay button, so to speak.

There was also another aspect to Nadia’s changed mood. Once she started understanding unit conversion, she was angry that she hadn’t gotten it before. It was a healthy, useful kind of anger. She was mad at herself for feeling daunted, for doubting her own abilities, for having given in to discouragement. Now that she’d conquered one recalcitrant subject, she’d be much less likely to let herself be daunted ever again.

Nadia went on to retake her math exam, and passed with flying colors. In the meantime, I had also started tutoring her younger brothers, Arman and Ali. Word got out to a few other family members and friends, and before long I had around ten students. Though I didn’t realize it at the time, the Khan Academy was mysteriously coming into being—was being pulled into being by the curiosity and needs of its students and their families. The invisible process of its going somewhat viral was already in the first tiny stage of gathering momentum.

All of my tutees, I’m proud to say, were soon doing work way beyond their grade levels—and I was hooked on teaching. I couldn’t help comparing the substance and satisfaction of my tutoring work to the money-based routines of my day job at the hedge fund. Now, I definitely don’t agree with the knee-jerk opinion that hedge funds are evil; the majority of the people in the field are actually highly intellectual, good people. Still, the focus of a workday in investing is not exactly social service. Was that really how I wanted to spend my life? Was that really the best use of my limited time on Earth?

I was in a bind. I was stuck in a job I really liked—it was challenging and intellectually and financially rewarding. But I had a nagging feeling that I was being held back from a calling I saw as far more worthwhile.

So I kept the day job and saved my pennies, looking forward to the time when I could afford to quit. In the meantime, I started experimenting with various techniques that might make me more efficient in serving my growing roster of tutees; again, I took a problem-solving, nuts-and-bolts approach to this—an engineer’s approach.

I tried to schedule Skype sessions with three or four students at a time. The logistics were unwieldy, and the lessons themselves not as effective as working one-to-one. To help automate things, I wrote some software that would generate questions and keep track of how each student did with the responses. I enjoyed writing the program, and it did give me valuable insights into where I should focus the time during the live sessions. As we will see later in our story, these techniques for gathering, organizing, and interpreting data have by now become useful and sophisticated tools. The software by itself, however, didn’t solve the problem of making the live sessions more scalable.

Then, just when I was starting to feel that I’d taken on too much and should probably back away, a friend came up with a suggestion: Why didn’t I record the lessons and post them on YouTube, so that each student could watch them at his or her convenience?

At once, I saw that the idea was… ridiculous! YouTube? YouTube was for cats playing the piano, not serious mathematics. A serious, systematic curriculum on YouTube? Clearly, a harebrained notion.

Some three thousand videos later, I still wish I’d thought of it myself.

No-Frills Videos

In character, in manner, in style, in all things, the supreme excellence is simplicity.


To those who believe that quality education requires showplace campuses and state-of-the-art classrooms, and is therefore a luxury item available only to wealthy communities in wealthy countries, I’d like to point out a few things about the early days of the Academy. For example, our headquarters was first a guest bedroom and then, more famously, a closet. True, it was a walk-in closet, with electrical outlets, room for a small desk, and even a window overlooking the garden. But it was a closet nonetheless. I thought of it as a kind of monk’s cell, a place to concentrate without distractions or the temptations of too much comfort.

In the formative years of the Academy, I was still muddling my way toward the most effective methods for presenting the video lessons. I was guided in part by my own taste and temperament, which tended toward the austere.

Early on, for example, I decided that I wanted the background of my computer “chalkboard” to be black. Even though it was now virtual, I felt that there was something magical about a blackboard. One of my key hopes was to remind students of the excitement of learning, to bring back the fun and even the suspense that ensued when the quest for understanding was seen as a kind of treasure hunt. What better way, graphically, to suggest this than by showing problems and solutions seeming to emerge from the void? Knowledge brought light out of darkness. With application and focus, students found answers where before there had been nothing but a blank.

Another formative and crucial decision had to do with the duration of the lessons. Back when I was tutoring Nadia over the phone, we had no particular time constraints. We talked until one or the other of us had to go, or until a certain concept had been covered, or until a certain level of frustration or mental fatigue had been reached; the length of our sessions was not determined by the clock. But when I started posting videos on YouTube, I had to abide by their guidelines. Although their rules have now changed for certain kinds of content, there was then a ten-minute limit for what the site would post. So my lessons were just about ten minutes long.

And it turned out that ten minutes, give or take, was the right length for them to be.

Let me make it clear that I did not discover this fact. I stumbled upon it by a mix of intuition and serendipity. But the truth is that well-credentialed educational theorists had long before determined that ten to eighteen minutes was about the limit of students’ attention spans.

Back in 1996, in a prestigious peer-reviewed journal called the National Teaching & Learning Forum, two professors from Indiana University, Joan Middendorf and Alan Kalish, published a remarkably detailed account of the ebbs and flows of students’ focus during a typical class period. It should be noted that this study centered on college students, and of course it was done before the age of texting and tweeting; presumably, the attention spans of younger people today have become even shorter, or certainly more challenged by distractions.

In any case, breaking the session down minute by minute, the professors determined that students needed a three- to five-minute period of settling down, which would be followed by ten to eighteen minutes of optimal focus. Then—no matter how good the teacher or how compelling the subject matter—there would come a lapse. In the vernacular, the kids would “lose it.” Attention would eventually return, but in ever briefer packets, falling “to three or four minutes towards the end of a standard lecture.”

An even earlier study, from 1985, had tested students on their recall of facts contained in a twenty-minute presentation. For purposes of scoring, the researcher broke the presentation into four segments of five minutes each. While you might expect that recall would be greatest regarding the final section of the presentation—the part heard most recently—in fact the result was strikingly opposite. Students remembered far more of what they’d heard at the very beginning of the lecture. By the fifteen-minute mark, they’d mostly zoned out.

My point here is that long before Khan Academy or YouTube even existed, solid academic research had gone a long way toward describing the length and shape and limits of students’ attention spans. Yet these findings—which were quite dramatic, consistent, and conclusive, and have never yet been refuted—went largely unapplied in the real world.

Curiously, in the Middendorf and Kalish study, even the researchers themselves shrank from applying their own conclusions. Having established that students’ attention maxed out at around ten or fifteen minutes, they still regarded it as a given that classroom sessions lasted an hour. They suggested, therefore, that teachers insert “change-ups” at various points in their lectures, “to restart the attention clock.” Perhaps, in the hands of skilled and resourceful teachers, these “change-ups” were effective in refreshing kids’ focus. Still, there was something gimmicky and beside the point about the whole idea; it went directly against the grain of the findings. If attention lasted ten or fifteen minutes, why did it remain a given that class periods were an hour?

Or again, if the “change-ups”—things like small-group discussions or active problem-solving—recharged student focus, why was the broadcast lecture still the dominant mode? Why was it still presumed that students would spend most of their day passively listening?

The bottom line is that the research—and, frankly, experience and common sense—pointed in a certain clear direction, but there was too much inertia to the already existing model to do anything about it.

Now, there are some exceptions. Many college courses in the humanities focus on discussion over lecture. Students read course material ahead of time and have a discussion in class. Harvard Business School took this to the extreme by pioneering case-based learning more than a hundred years ago, and many business schools have since followed suit. There are no lectures there, not even in subjects like accounting or finance. Students read a ten- to twenty-page description of a particular company’s or person’s circumstance—called a “case”—on their own time and then participate in a discussion/debate in class (where attendance is mandatory). Professors are there to facilitate the discussion, not to dominate it. I can tell you from personal experience that despite there being eighty students in the room, you cannot zone out. Your brain is actively processing what your peers are saying while you try to come to your own conclusions so that you can contribute during the entire eighty-minute session. The time goes by faster than you want it to; students are more engaged than in any traditional classroom I’ve ever been a part of.

Most importantly, the ideas that you and your peers collectively generate stick. To this day, comments and ways of thinking about a problem that my peers shared with me (or that I shared during class) nearly ten years ago come back to me as I try to help manage the growth and opportunities surrounding the Khan Academy.

Focusing on the Content

Art is the elimination of the unnecessary.


The duration of the YouTube lessons is hardly the only instance in which Khan Academy teaching methods—arrived at largely by serendipity and intuition—turned out to be neither more nor less than the implementation of sound pedagogic research that had been accepted in theory but never really been applied. As we’ll see, this is a recurring theme.

For right now, however, I’d like to introduce another factor that was a key consideration in shaping my approach to teaching: cost. I was bankrolling the Academy solely from my personal savings. I loved teaching, but I didn’t want to go broke doing it. When it came to posting the video lessons, I wanted to keep the equipment and production costs to an absolute minimum.

It was partly for this reason—and not because of some preexisting theory—that I decided that I would never be pictured in the lessons. I didn’t at the time own a suitable video camera, and I didn’t want to buy one. It seemed like a slippery slope. If I had a camera, I would have to worry about the lighting. If I had good lighting, I would have to give thought to what I was wearing and whether I had spinach in my teeth. The danger was that the whole process would become more like making movies than tutoring students. Tutoring is intimate. You talk with someone, not at someone. I wanted students to feel like they were sitting next to me at the kitchen table, elbow to elbow, working out problems together. I didn’t want to appear as a talking head at a blackboard, lecturing from across the room. So it was determined that students would never see me but only hear my voice, while the visuals would be nothing except my scrawls (and occasional historic images) on the black electronic chalkboard. Students would see the same thing I was seeing.

Human beings are also hardwired to focus on faces. We are constantly scanning the facial expressions of those around us to get information about the emotional state of the room and our place in it. We seem to be hardwired to meet each other’s gazes, to read lips even as we are listening. Anyone who has ever raised a baby has noticed its particular attention while looking at its mother; indeed, its parents’ faces are probably the very first things a newborn manages to focus on.

So if faces are so important to human beings, why exclude them from videos? Because they are a powerful distraction from the concepts being discussed. What, after all, is more distracting than a pair of blinking human eyes, a nose that twitches, and a mouth that moves with every word? Put a face in the same frame as an equation, and the eye will bounce back and forth between the two. Concentration will wander. Haven’t we all had the experience of losing the thread of a conversation because we homed in on the features of the person we were talking with rather than paying steady attention to what was being said?

This is not to say that faces—both the teacher’s and the student’s—are unimportant to the teaching process. On the contrary, face time shared by teachers and students is one of the things that humanizes the classroom experience, that lets both teachers and students shine in their uniqueness. Through facial expressions, teachers convey empathy, approval, and all the many nuances of concern. Students, in turn, reveal their stresses and uncertainties, as well as their pleasure when a concept finally becomes clear.


Excerpted from The One World Schoolhouse by Salman Khan Copyright © 2012 by Salman Khan. Excerpted by permission.
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