This first volume of PISA 2009 survey results provides comparable data on 15-year-olds' performance on reading, mathematics and science across 65 countries. The volume opens with an introduction explaining what PISA is and how PISA 2009 is different from previous PISA surveys. The introduction also explains what PISA 2009 measures and how. A reader's guide provides information needed to interpret the data. Chapter 2 provides a summary of the findings related to performance in reading, the focus of the 2009 survey. Chapter 3 provides a summary of the findings related to performance in mathematics and science. A final chapter explores policy implications in five areas: low performance, pursuing excellence, strengths and weaknesses in different kinds of reading, student performance in math and science, and the potential to improve performance across the world. Annexes provide detailed statistical data and technical information.