In character, in manner, in style, in all things, the supreme excellence is simplicity.
—HENRY WADSWORTH LONGFELLOW
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.”1
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.