First, a few acronyms: Andreas Schleicher heads the Program for International Student Assessment (PISA) at the Organization for Economic Co-operation and Development (OECD). What it means is: He's designed a test, given to hundreds of thousands of 15-year-olds around the world (the most recent covered almost 70 nations), that offers unprecedented insight into how well national education systems are preparing their students for adult life. As The Atlantic puts it, the PISA test "measured not students’ retention of facts, but their readiness for 'knowledge worker' jobs—their ability to think critically and solve real-world problems."
The results of the PISA test, given every three years, are fed back to governments and schools so they can work on improving their ranking. And the data has inspired Schleicher to become a vocal advocate for the policy changes that, his research suggests, make for great schools.