Because effective teaching is incredibly complex.

And if they don’t understand Algebra, they can’t understand Calculus. If they don’t understand functions, they won’t understand Algebra. If students don’t understand slope at the conceptual level, they won’t understand functions. To the lay person this may seem like a trivial distinction, but slope is one of the most fundamental concepts in secondary math. In fact, slope is a rate that describes how two variables change in relation to one another: how a car’s distance changes over time (miles per additional hour) how the price of an iPod changes as you buy more memory (dollars per additional gigabyte). Take Khan’s explanation of slope, which he defines as “rise over run.” An effective math teacher will point out that “rise over run” isn’t the definition of slope at all but merely a way to calculate it. That’s a heroic achievement.īut there’s a problem: the videos aren’t very good.

and all of a sudden Khan Academy, a collection of low-res videos offering step-by-step instructions for how to solve math problems, was being hailed as the Next Big Thing in education.Īnd big it is: Khan Academy boasts almost 3,300 videos that have been viewed over 160 million times. Then the San Jose Mercury, 60 Minutes, the New York Times.

But Ann Doerr, wife of venture capitalist John Doerr, picked up on it.

He didn’t set out to become one of the biggest celebrities in education but simply to help his cousins with their math homework.

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