PISA  is a three-yearly survey of 15-year-olds in the 30 OECD member countries and 35 partner countries . It assesses the extent to which students near the end of compulsory education have acquired the knowledge and skills essential in everyday life. They are tested in the domains of reading, mathematical and scientific literacy and complete a background questionnaire. For each cycle one domain is focused on more than the others. The first data collection took place in 2000, the second in 2003 and the third in 2006. The fourth cycle is in progress for 2009.

PISA tests students on their ability to adapt the knowledge they acquire at school to real-life situations as opposed to how they master a specific curriculum. Factors influencing their performance and potential for lifelong learning are also explored in the background questionnaire in which they are asked about their approaches to learning and their social background. The organisation of schools is also taken into account through a questionnaire filled out by school principals.

All 30 OECD member countries participate in PISA. The number of partner countries has varied however. In PISA 2000, 13 partner countries participated.  Eleven partner countries participated in PISA 2003, 27 in PISA 2006, with 35 particpating in the PISA 2009 cycle. Between 4,500 and 10,000 students are tested in each cycle. Students are selected from a random sample of schools (public and private) and are selected according to their age (from 15 years and 3 months to 16 years and 2 months at the beginning of the assessment) as opposed to which grade they belong to.

As well as filling out the background questionnaire, students in each country carry out paper-and-pencil tests. Responses are either multiple choice or open-ended. For each assessment, more testing time is devoted to the main domain than the others. The design and implementation of the survey is carried out by an International Consortium working closely with National Project Managers. It reports to both the OECD Secretariat which has overall managerial responsibility for the project and the PISA Governing Board which establishes the project’s policy directions.