Definition: Programme for International Student Assessment
Purchasing power parities
The programme is managed by the OECD. Tests are administered to 15 year olds in schools and cover three topics: mathematics, reading and science. Typically between 4,500 and 10,000 students sit the tests per country. The tests are held every three years and there have been four assessments to date: 2000 (43 countries), 2003 (41 countries), 2006 (57 countries), and 2009 (65 countries of which 43 participate in the Eurostat–OECD PPP [Purchasing power paritity] Programme). PISA provides assessments that are corrected for the economic, social and cultural status (ESCS) of students thereby making possible a better evaluation of the quality of the teaching. The quality adjustments made at the primary and secondary levels of education for the Eurostat-OECD output method are based on ESCS corrected PISA scores.
Eurostat, Organization for Economic Cooperation and Development (OECD), "Eurostat-OECD Methodological Manual on Purchasing Power Parities", Publications Office of the European Union, Luxembourg, 2012