The Smartest Kids In The World: And How They Got That Way

In the 1980s, a shift toward the social sciences as valid sources of data on education led to the creation of the Programme for International Student Assessment (PISA), an exam for 15-year-olds created by Andrew Schleicher in 2000 and run by the Organisation for Economic Co-operation and Development (OECD). It is administered every three years in 81 countries around the world, including the United States, Germany, Mexico, Spain, Singapore, Zambia, the United Kingdom, and Japan. 

Ripley chose the PISA as a basis for her international comparison because it provides a standard measure of achievement in key subjects and skills. The test was designed to measure students’ aptitude in math, reading, and science, as well as their ability to think creatively, reason with data, interpret texts, solve problems, and apply learning to real‑world situations. The PISA’s design emphasizes these skills as essential in modern economies. Consistent with the philosophy of lifelong learning, the PISA is constantly being improved, expanded, and updated.

Because the PISA does not have set answers, it must be graded by people rather than machines, and this has drawn controversy for its perceived subjectivity. For example, a 2025 study by Norwegian researchers compared question features (such as cognitive processes, text source, format, and text type) across 71 countries to see how these features affect the exam’s difficulty and whether the framework is valid across diverse cultural and linguistic contexts.