Watching videos online usually means goofing off. But over the past few years, millions of decidedly enterprising people have turned on their computers to watch, of all things, math and science ...

The stellar Khan Academy offers free, well-structured online courses in a variety of subjects that you'll find in US schools, and serves as a reliable source for anyone with a hunger to learn. Where ...

In previous posts, I have summed up my position on Khan Academy as follows: Khan Academy teaches only one part of mathematics—procedures—and that isn’t the most important part. Writing about ...