Too many teachers in Ontario; too few in Sri Lanka. 70 million children without basic education. Examination chaos. Spiraling university costs. Girls excelling in math; girls lagging in math. Brain drain. Millions of people of all ages want to better themselves through education. What barriers do they face? What works and what doesn’t? How to find out? From village classrooms to the halls of the Ivy League, rigorous data can help us get it right.