This strange new test called PISA, which stood for the Program for International Student Assessment. Instead of a typical test question, which might ask which combination of coins you needed to buy something, PISA asked you to design your own coins, right there in the test booklet.

PISA was developed by a kind of think tank for the developed world, called the Organization for Economic Co-operation and Development, and the scientist at the center of the experiment was Andreas Schleicher.