Two million children in the US are taught by their parents or private tutors at home.

In surveys of standardised achievement tests over the past 20 years, home-schooled children on average scored about 30 percentiles above the median. And of those who went on to higher education, two-thirds earned a degree compared to just over half of their classmates. 

Al Jazeera's Tom Ackerman reports from Washington, DC.

Source: Al Jazeera