Web tutors pass with flying colours

Not that long ago, Salman Khan thought YouTube was only “for cats playing the piano. No place for serious mathematics.”

With more than 3.5 million students watching his educational videos every month, the founder of Khan Academy has long since changed his mind.

While living in Boston, Khan began the online academy as a way of tutoring his cousins in New Orleans in mathematics. It has grown exponentially, helped by hordes of grateful parents whose dim memories of algebra or trigonometry are not enough to help with their children’s homework. While Khan Academy is the most widely known, there are a host of similar websites aimed at students and teachers.

When Bill Gates told the 2010 Aspen Ideas Festival that he watched Khan Academy videos with his children, the site’s traffic spiked higher overnight. At the time Khan was still making short films out of a closet in his home. Nine months after taking a year off from his job as a hedge fund analyst, he was “beginning to think about polishing my resume.”

Instead, with backing from the Gates Foundation and Google, whose $2 million donation is paying for his material to be translated into 10 languages, Khan now hopes to change the way students learn from kindergarten all the way to graduate school. Khan calls his revolutionary idea “the flip” and the basic premise – that classroom lectures followed by homework followed by exams is a recipe for educational failure – is gaining momentum.

“If I just want to tell you stuff, a lecture is very useful, but if I really want you to learn something it’s not that useful,” said Richard Baraniuk, professor of electrical engineering at Rice University and founder of Connexions, an open-source website for college textbooks. Though Baraniuk prefers the term “reverse instruction,” he sees Khan Academy as fitting into an approach pioneered by Carl Wieman, a Nobel laureate in physics serving as an adviser to the White House. In a paper titled “Why Not Try a Scientific Approach to Scientific Education?”

Wieman cited data showing that students who take an introductory physics course typically know less physics when they finish – and that “if anything, the effect of taking an introductory college chemistry course is even worse.” Traditional teaching methods simply do not allow “enough time to develop the long-term memory structures required for subject mastery,” Wieman wrote.

Khan agrees. “In a traditional classroom, what’s fixed is the amount of time you spend on a subject. The variable is how well you learn it,” he said during an interview on Skype. “But when you think about all the things you learn outside a classroom – riding a bike, sports, playing an instrument – what you want to achieve is a certain mastery.”

The videos, however, are only the beginning. From the start, Khan was writing software that allowed him to track the progress his cousins were making. Underlying the whole enterprise is a “knowledge map” – a chart offering exercises leading, step by step, from simple addition to linear algebra.

In a speech last month, Khan explained: “Each square is a different concept. The videos are there if you need help. The idea is you keep doing the problems till you’ve mastered the concept, and then you go on to the next concept. It’s how every video game works.” The software lets teachers and parents see where students excel – and where they need help.

Invited to pilot his approach by the Los Altos, California, public school district, Khan discovered that students were able to progress further and with more confidence by “flipping” the sequence of activities – asking students to try the problems online before class, and then having teachers work individually or in small groups on just those areas students found difficult.

“But they were all still working in lockstep,” he said, adding that ideally “you would have students all working at their own pace,” helping each other in class and online, allowing the teachers to use class time far more effectively. Some critics have claimed Khan is trying to make teachers obsolete. “That’s not what we’re about,” he responded.

Marshall Smith, who served as undersecretary of education in the Clinton administration, said that technology “gives teachers room to go deeper.” Recently retired as programme officer of the Hewlett Foundation, Smith is an admirer of Khan Academy. But he warned that innovation would not come easily.

“There are a lot of higher education institutions where the teaching just isn’t very good, where the teachers rattle on as they’ve been doing for years, and where, especially in the sciences, the teachers just don’t keep up,” he said.

Helping teachers to keep up was one of the driving forces behind PhET, a website at the University of Colorado founded by Weiman that uses interactive computer simulations to teach physics, chemistry, biology and earth sciences. Initially aimed at college students, PhET, which stands for Physics Education Technology, attracts 25 million visitors a year. Like Khan Academy lectures, the simulations “can be used offline,” said Katherine Perkins, the project’s director.

Baraniuk argues that anything beyond the first few rows is “distance learning.”
If you have a class of 250 students, the first three rows are getting a high quality experience,” he said. “Everybody else is just watching.”

For Baraniuk, a key issue is quality control. “PhET happens to be founded by a Nobel Prize-winning physicist. So he probably knows physics,” he said. ‘`And if you loved Sal Khan’s algebra, you’ll probably love his geometry.

Connexions is open to anybody who wants to submit material’' – a strategy Baraniuk calls “in-reach.” “We’re enlisting professional societies,” he said. Khan has recently broadened his curriculum to include art history, civics, history and “micro- and macroeconomics, drawing on my hedge-fund experience.”

And he has taken a different approach, allowing users to post comments. Urging students to bring “a healthy dose of skepticism – this is just one point of view,” Khan seems content to rely on the wisdom of crowds. “Our material isn’t just reviewed by Americans, or a few professors. It’s been reviewed by the world,” he said.