The Organisation for Economic Co-operation and Development (OECD) released the results of its fifth Programme for International Student Assessment (PISA) study yesterday, with few surprises. Conducted every three years, the test compares the performance of 15-year-olds in reading, mathematics, and science in countries and cities around the world. Once again, Asian students dominated the top rankings, with those in Shanghai, China scoring the highest marks across the board. The United States showed little change, but its rankings have fallen as other countries have done better. This year it was even surpassed by a newcomer to the test – Vietnam.