FOR a ten-year-old, Amartya is a thoughtful chap. One Monday morning at the Khan Lab School (KLS) in Mountain View, California, he explains that his maths is “pretty strong” but he needs to work on his writing. Not to worry, though; Amartya has a plan. He will practise grammar online, book a slot with an English teacher and consult his mentor. Later he will e-mail your correspondent to ask for help, too.This is the sort of pluck KLS produces. Its pupils do not have homework or report cards or spend all day in classrooms. They are not stratified by age; they share common spaces as they pursue individual goals and schedules, using software built by in-house developers to take tests and watch video lessons from the school’s sister organisation, Khan Academy, which makes online tutorials. Half the teachers act like tutors, helping with academic work. The rest mentor pupils in character traits such as curiosity and self-awareness.